:root {
  color-scheme: light;
  --ink: #172033;
  --muted: #667085;
  --line: #d7dee8;
  --paper: #ffffff;
  --mist: #f6f8fb;
  --brand: #0f766e;
  --brand-strong: #115e59;
  --brand-soft: #d9f7f1;
  --accent: #b45309;
  --accent-soft: #fff3d4;
  --blue: #2458d3;
  --blue-soft: #e2eaff;
  --bad: #be123c;
  --bad-soft: #ffe4e9;
  --good: #047857;
  --good-soft: #dff7ea;
  --shadow: 0 18px 46px rgba(23, 32, 51, 0.12);
  --radius: 8px;
  --content: min(1180px, calc(100vw - 36px));
  font-family: "Segoe UI", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
}

body.book-bsks {
  --ink: #24233a;
  --muted: #6f6d83;
  --line: #ddd9ee;
  --paper: #fffefd;
  --mist: #f4f1fb;
  --brand: #5542ad;
  --brand-strong: #33246e;
  --brand-soft: #ebe7ff;
  --accent: #c98236;
  --accent-soft: #fff0d8;
  --blue: #2c6eac;
  --blue-soft: #e5f0fb;
  --shadow: 0 15px 38px rgba(51, 36, 110, 0.13);
  --app-bg:
    linear-gradient(90deg, rgba(85, 66, 173, 0.055) 1px, transparent 1px),
    linear-gradient(180deg, rgba(201, 130, 54, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, #fffefd 0%, #f4f1fb 64%, #fff7e9 100%);
  background-size: 44px 44px, 44px 44px, auto;
}

body.book-bsks .topbar {
  border-top: 4px solid var(--brand);
  border-bottom-color: rgba(85, 66, 173, 0.22);
}

body.book-bsks .brand-mark {
  border: 1px solid var(--brand-strong);
  border-radius: 4px;
  background: var(--brand-strong);
  color: #ffe1a9;
  font-family: Consolas, "Courier New", monospace;
  box-shadow: 4px 4px 0 rgba(201, 130, 54, 0.2);
}

body.book-bsks .nav a.active,
body.book-bsks .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--accent);
}

body.book-bsks .hero-band {
  color: var(--ink);
  background:
    linear-gradient(112deg, rgba(255, 255, 255, 0.98) 0 58%, rgba(238, 234, 255, 0.9) 58% 100%),
    linear-gradient(90deg, rgba(85, 66, 173, 0.08) 1px, transparent 1px),
    linear-gradient(180deg, rgba(85, 66, 173, 0.08) 1px, transparent 1px),
    #faf8ff;
  background-size: auto, 36px 36px, 36px 36px, auto;
  border-bottom: 7px solid var(--brand-strong);
}

body.book-bsks .hero-band::before {
  content: "PHD";
  position: absolute;
  right: 4vw;
  bottom: -26px;
  color: rgba(85, 66, 173, 0.08);
  font-family: Consolas, "Courier New", monospace;
  font-size: 118px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-bsks .hero-grid,
body.book-bsks .book-preview {
  position: relative;
  z-index: 1;
}

body.book-bsks .hero-grid p {
  color: #65617b;
}

body.book-bsks .hero-band .secondary-button,
body.book-bsks .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.92);
  border-color: rgba(85, 66, 173, 0.28);
}

body.book-bsks .book-preview {
  padding: 12px;
  border: 1px solid rgba(85, 66, 173, 0.28);
  border-top: 7px solid var(--accent);
  border-radius: 5px;
  background: #fff;
  box-shadow: 12px 12px 0 rgba(85, 66, 173, 0.1);
}

body.book-bsks .panel,
body.book-bsks .stat,
body.book-bsks .course-item,
body.book-bsks .practice-item,
body.book-bsks .paper-card,
body.book-bsks .question,
body.book-bsks .review-card,
body.book-bsks .history-row,
body.book-bsks .empty-state {
  border-color: rgba(85, 66, 173, 0.2);
}

body.book-bsks .stat {
  border-top: 4px solid var(--accent);
  background: linear-gradient(135deg, #ffffff, #f0edff);
}

body.book-bsks .stat strong {
  color: var(--brand-strong);
}

body.book-bsks .course-item.active,
body.book-bsks .practice-item.active,
body.book-bsks .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(105deg, var(--brand-soft), var(--accent-soft));
}

body.book-zsb {
  --ink: #1c3038;
  --muted: #60737a;
  --line: #cfe0e2;
  --paper: #fbfefd;
  --mist: #edf7f7;
  --brand: #0d7480;
  --brand-strong: #07525e;
  --brand-soft: #d9f1ef;
  --accent: #d35e43;
  --accent-soft: #ffebe2;
  --blue: #276aa2;
  --blue-soft: #e2f0fa;
  --shadow: 0 15px 38px rgba(7, 82, 94, 0.13);
  --app-bg:
    linear-gradient(90deg, rgba(13, 116, 128, 0.055) 1px, transparent 1px),
    linear-gradient(180deg, rgba(211, 94, 67, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, #fbfefd 0%, #edf7f7 62%, #fff3ed 100%);
  background-size: 42px 42px, 42px 42px, auto;
}

body.book-zsb .topbar {
  border-top: 4px solid var(--brand);
  border-bottom-color: rgba(13, 116, 128, 0.22);
}

body.book-zsb .brand-mark {
  border: 1px solid var(--brand-strong);
  border-radius: 4px;
  background: var(--brand-strong);
  color: #ffd6bf;
  font-family: Consolas, "Courier New", monospace;
  box-shadow: 4px 4px 0 rgba(211, 94, 67, 0.2);
}

body.book-zsb .nav a.active,
body.book-zsb .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--accent);
}

body.book-zsb .hero-band {
  color: var(--ink);
  background:
    linear-gradient(112deg, rgba(255, 255, 255, 0.98) 0 58%, rgba(219, 241, 239, 0.92) 58% 100%),
    linear-gradient(90deg, rgba(13, 116, 128, 0.08) 1px, transparent 1px),
    linear-gradient(180deg, rgba(13, 116, 128, 0.08) 1px, transparent 1px),
    #f8fdfd;
  background-size: auto, 36px 36px, 36px 36px, auto;
  border-bottom: 7px solid var(--brand-strong);
}

body.book-zsb .hero-band::before {
  content: "2+2";
  position: absolute;
  right: 4vw;
  bottom: -26px;
  color: rgba(13, 116, 128, 0.08);
  font-family: Consolas, "Courier New", monospace;
  font-size: 108px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-zsb .hero-grid,
body.book-zsb .book-preview {
  position: relative;
  z-index: 1;
}

body.book-zsb .hero-grid p {
  color: #526b72;
}

body.book-zsb .hero-band .secondary-button,
body.book-zsb .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.92);
  border-color: rgba(13, 116, 128, 0.28);
}

body.book-zsb .book-preview {
  padding: 12px;
  border: 1px solid rgba(13, 116, 128, 0.28);
  border-top: 7px solid var(--accent);
  border-radius: 5px;
  background: #fff;
  box-shadow: 12px 12px 0 rgba(13, 116, 128, 0.1);
}

body.book-zsb .panel,
body.book-zsb .stat,
body.book-zsb .course-item,
body.book-zsb .practice-item,
body.book-zsb .paper-card,
body.book-zsb .question,
body.book-zsb .review-card,
body.book-zsb .history-row,
body.book-zsb .empty-state {
  border-color: rgba(13, 116, 128, 0.2);
}

body.book-zsb .stat {
  border-top: 4px solid var(--accent);
  background: linear-gradient(135deg, #ffffff, #eaf7f6);
}

body.book-zsb .stat strong {
  color: var(--brand-strong);
}

body.book-zsb .course-item.active,
body.book-zsb .practice-item.active,
body.book-zsb .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(105deg, var(--brand-soft), var(--accent-soft));
}

body.book-syyh {
  --ink: #1d2a3a;
  --muted: #687589;
  --line: #d4dbe4;
  --paper: #ffffff;
  --mist: #f1f4f8;
  --brand: #1f4f78;
  --brand-strong: #173858;
  --brand-soft: #e2edf7;
  --accent: #c68827;
  --accent-soft: #fff1d2;
  --blue: #2c78a7;
  --blue-soft: #e3f2fa;
  --shadow: 0 15px 36px rgba(29, 52, 76, 0.13);
  --app-bg:
    linear-gradient(90deg, rgba(31, 79, 120, 0.055) 1px, transparent 1px),
    linear-gradient(180deg, rgba(198, 136, 39, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, #fbfcfe 0%, #f1f5fa 62%, #fff8e9 100%);
  background-size: 44px 44px, 44px 44px, auto;
}

body.book-syyh .topbar {
  border-top: 4px solid var(--brand);
  border-bottom-color: rgba(31, 79, 120, 0.22);
  background: rgba(255, 255, 255, 0.96);
}

body.book-syyh .brand-mark {
  border: 1px solid #173858;
  border-radius: 4px;
  background: #173858;
  color: #f9d994;
  font-family: Consolas, "Courier New", monospace;
  box-shadow: 4px 4px 0 rgba(198, 136, 39, 0.2);
}

body.book-syyh .nav a.active,
body.book-syyh .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--accent);
}

body.book-syyh .hero-band {
  color: var(--ink);
  background:
    linear-gradient(112deg, rgba(255, 255, 255, 0.98) 0 60%, rgba(255, 241, 210, 0.9) 60% 100%),
    linear-gradient(90deg, rgba(31, 79, 120, 0.08) 1px, transparent 1px),
    linear-gradient(180deg, rgba(31, 79, 120, 0.08) 1px, transparent 1px),
    #f6f9fc;
  background-size: auto, 36px 36px, 36px 36px, auto;
  border-bottom: 7px solid #173858;
}

body.book-syyh .hero-band::before {
  content: "BANK";
  position: absolute;
  right: 4vw;
  bottom: -26px;
  color: rgba(31, 79, 120, 0.08);
  font-family: Consolas, "Courier New", monospace;
  font-size: 118px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-syyh .hero-grid,
body.book-syyh .book-preview {
  position: relative;
  z-index: 1;
}

body.book-syyh .hero-grid p {
  color: #53667b;
}

body.book-syyh .hero-band .secondary-button,
body.book-syyh .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.9);
  border-color: rgba(31, 79, 120, 0.28);
}

body.book-syyh .book-preview {
  padding: 12px;
  border: 1px solid rgba(31, 79, 120, 0.28);
  border-top: 7px solid var(--accent);
  border-radius: 5px;
  background: #fff;
  box-shadow: 12px 12px 0 rgba(31, 79, 120, 0.1);
}

body.book-syyh .panel,
body.book-syyh .stat,
body.book-syyh .course-item,
body.book-syyh .practice-item,
body.book-syyh .paper-card,
body.book-syyh .question,
body.book-syyh .review-card,
body.book-syyh .history-row,
body.book-syyh .empty-state {
  border-color: rgba(31, 79, 120, 0.2);
}

body.book-syyh .stat {
  border-top: 4px solid var(--accent);
  background: linear-gradient(135deg, #ffffff, #eef5fb);
}

body.book-syyh .stat strong {
  color: var(--brand-strong);
}

body.book-syyh .course-item.active,
body.book-syyh .practice-item.active,
body.book-syyh .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(105deg, var(--brand-soft), var(--accent-soft));
}

body.book-dwqy {
  --ink: #182b35;
  --muted: #61757c;
  --line: #cddcdf;
  --paper: #fbfefd;
  --mist: #edf6f5;
  --brand: #087f83;
  --brand-strong: #07585d;
  --brand-soft: #daf2ee;
  --accent: #d18a2e;
  --accent-soft: #fff0d2;
  --blue: #236ba5;
  --blue-soft: #e0eff9;
  --shadow: 0 15px 36px rgba(8, 91, 96, 0.13);
  --app-bg:
    linear-gradient(90deg, rgba(8, 127, 131, 0.06) 1px, transparent 1px),
    linear-gradient(180deg, rgba(35, 107, 165, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, #fafdfe 0%, #eff8f6 60%, #fff7e7 100%);
  background-size: 40px 40px, 40px 40px, auto;
}

body.book-dwqy .topbar {
  border-top: 4px solid var(--brand);
  border-bottom-color: rgba(8, 127, 131, 0.22);
  background: rgba(251, 254, 253, 0.96);
}

body.book-dwqy .brand-mark {
  border: 1px solid #07585d;
  border-radius: 4px;
  background: #07585d;
  color: #f5d58f;
  font-family: Consolas, "Courier New", monospace;
  box-shadow: 4px 4px 0 rgba(35, 107, 165, 0.18);
}

body.book-dwqy .nav a.active,
body.book-dwqy .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--accent);
}

body.book-dwqy .hero-band {
  color: var(--ink);
  background:
    linear-gradient(115deg, rgba(255, 255, 255, 0.98) 0 58%, rgba(218, 242, 238, 0.88) 58% 100%),
    linear-gradient(90deg, rgba(8, 127, 131, 0.08) 1px, transparent 1px),
    linear-gradient(180deg, rgba(35, 107, 165, 0.08) 1px, transparent 1px),
    #f5fbfa;
  background-size: auto, 34px 34px, 34px 34px, auto;
  border-bottom: 7px solid #07585d;
}

body.book-dwqy .hero-band::before {
  content: "GRID";
  position: absolute;
  right: 4vw;
  bottom: -26px;
  color: rgba(8, 127, 131, 0.08);
  font-family: Consolas, "Courier New", monospace;
  font-size: 124px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-dwqy .hero-grid,
body.book-dwqy .book-preview {
  position: relative;
  z-index: 1;
}

body.book-dwqy .hero-grid p {
  color: #4f6970;
}

body.book-dwqy .hero-band .secondary-button,
body.book-dwqy .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.9);
  border-color: rgba(8, 127, 131, 0.28);
}

body.book-dwqy .book-preview {
  padding: 12px;
  border: 1px solid rgba(8, 127, 131, 0.28);
  border-top: 7px solid var(--accent);
  border-radius: 5px;
  background: #fbfefd;
  box-shadow: 12px 12px 0 rgba(8, 127, 131, 0.11);
}

body.book-dwqy .panel,
body.book-dwqy .stat,
body.book-dwqy .course-item,
body.book-dwqy .practice-item,
body.book-dwqy .paper-card,
body.book-dwqy .question,
body.book-dwqy .review-card,
body.book-dwqy .history-row,
body.book-dwqy .empty-state {
  border-color: rgba(8, 127, 131, 0.2);
}

body.book-dwqy .stat {
  border-top: 4px solid var(--brand);
  background: linear-gradient(135deg, #ffffff, #eaf7f5);
}

body.book-dwqy .stat strong {
  color: var(--brand-strong);
}

body.book-dwqy .course-item.active,
body.book-dwqy .practice-item.active,
body.book-dwqy .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(105deg, var(--brand-soft), var(--accent-soft));
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background: var(--app-bg, linear-gradient(180deg, rgba(15, 118, 110, 0.08), transparent 340px), var(--mist));
}

body.book-czsx {
  --ink: #243041;
  --muted: #64748b;
  --line: #d8e3ef;
  --paper: #ffffff;
  --mist: #f7fbff;
  --brand: #158f8b;
  --brand-strong: #0f6865;
  --brand-soft: #dff8f6;
  --accent: #d97706;
  --accent-soft: #fff0c7;
  --blue: #2f6fe4;
  --blue-soft: #e7efff;
  --shadow: 0 16px 38px rgba(31, 80, 122, 0.12);
  --app-bg:
    linear-gradient(90deg, rgba(47, 111, 228, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, rgba(21, 143, 139, 0.06) 1px, transparent 1px),
    linear-gradient(180deg, #fcfeff 0%, #f3fbfb 48%, #fff8e6 100%);
  background-size: 36px 36px, 36px 36px, auto;
}

body.book-yyjf {
  --ink: #1f2937;
  --muted: #64748b;
  --line: #d7dee8;
  --paper: #ffffff;
  --mist: #f7f9fc;
  --brand: #244a78;
  --brand-strong: #17365c;
  --brand-soft: #e5eef9;
  --accent: #bd8738;
  --accent-soft: #fff2d7;
  --blue: #315fd6;
  --blue-soft: #e7edff;
  --shadow: 0 16px 38px rgba(36, 74, 120, 0.13);
  --app-bg:
    linear-gradient(90deg, rgba(36, 74, 120, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, rgba(189, 135, 56, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, #fcfdff 0%, #f1f6fd 58%, #fff8e9 100%);
  background-size: 40px 40px, 40px 40px, auto;
}

body.book-yyjf .topbar {
  border-top: 4px solid var(--brand);
  border-bottom-color: rgba(36, 74, 120, 0.2);
  background: rgba(255, 255, 255, 0.96);
}

body.book-yyjf .brand-mark {
  border: 1px solid var(--brand-strong);
  border-radius: 4px;
  background: var(--brand-strong);
  color: #f8d99b;
  font-family: Consolas, "Courier New", monospace;
  box-shadow: 4px 4px 0 rgba(189, 135, 56, 0.2);
}

body.book-yyjf .nav a.active,
body.book-yyjf .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--accent);
}

body.book-yyjf .hero-band {
  color: var(--ink);
  background:
    linear-gradient(112deg, rgba(255, 255, 255, 0.98) 0 60%, rgba(229, 238, 249, 0.92) 60% 100%),
    repeating-linear-gradient(0deg, transparent 0 28px, rgba(36, 74, 120, 0.055) 28px 29px),
    #f6f9fd;
  border-bottom: 7px solid var(--brand-strong);
}

body.book-yyjf .hero-band::before {
  content: "SYNTAX";
  position: absolute;
  right: 4vw;
  bottom: -24px;
  color: rgba(36, 74, 120, 0.08);
  font-family: Consolas, "Courier New", monospace;
  font-size: 86px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-yyjf .hero-grid,
body.book-yyjf .book-preview {
  position: relative;
  z-index: 1;
}

body.book-yyjf .hero-grid p {
  color: #53667b;
}

body.book-yyjf .hero-band .secondary-button,
body.book-yyjf .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.9);
  border-color: rgba(36, 74, 120, 0.26);
}

body.book-yyjf .book-preview {
  padding: 12px;
  border: 1px solid rgba(36, 74, 120, 0.26);
  border-top: 7px solid var(--accent);
  border-radius: 5px;
  background: #fff;
  box-shadow: 12px 12px 0 rgba(36, 74, 120, 0.1);
}

body.book-yyjf .panel,
body.book-yyjf .stat,
body.book-yyjf .course-item,
body.book-yyjf .practice-item,
body.book-yyjf .paper-card,
body.book-yyjf .question,
body.book-yyjf .review-card,
body.book-yyjf .history-row,
body.book-yyjf .empty-state {
  border-color: rgba(36, 74, 120, 0.2);
}

body.book-yyjf .stat {
  border-top: 4px solid var(--accent);
  background: linear-gradient(135deg, #ffffff, #eef4fb);
}

body.book-yyjf .stat strong {
  color: var(--brand-strong);
}

body.book-yyjf .course-item.active,
body.book-yyjf .practice-item.active,
body.book-yyjf .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(105deg, var(--brand-soft), var(--accent-soft));
}

body.book-czyd {
  --ink: #172b3a;
  --muted: #607381;
  --line: #d6e2ea;
  --paper: #ffffff;
  --mist: #f3f9fc;
  --brand: #147a9c;
  --brand-strong: #0b536d;
  --brand-soft: #dff3fa;
  --accent: #e5792f;
  --accent-soft: #fff0e2;
  --blue: #2f6fe4;
  --blue-soft: #e7efff;
  --shadow: 0 16px 38px rgba(20, 122, 156, 0.13);
  --app-bg:
    linear-gradient(90deg, rgba(20, 122, 156, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, rgba(229, 121, 47, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, #fbfeff 0%, #eff8fb 58%, #fff5ec 100%);
  background-size: 38px 38px, 38px 38px, auto;
}

body.book-czyd .topbar {
  border-top: 4px solid var(--brand);
  border-bottom-color: rgba(20, 122, 156, 0.22);
  background: rgba(255, 255, 255, 0.96);
}

body.book-czyd .brand-mark {
  border: 1px solid var(--brand-strong);
  border-radius: 4px;
  background: var(--brand-strong);
  color: #c9f2ff;
  font-family: Consolas, "Courier New", monospace;
  box-shadow: 4px 4px 0 rgba(229, 121, 47, 0.2);
}

body.book-czyd .nav a.active,
body.book-czyd .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--accent);
}

body.book-czyd .hero-band {
  color: var(--ink);
  background:
    linear-gradient(112deg, rgba(255, 255, 255, 0.98) 0 58%, rgba(223, 243, 250, 0.92) 58% 100%),
    repeating-linear-gradient(90deg, transparent 0 32px, rgba(20, 122, 156, 0.055) 32px 33px),
    #f5fbfd;
  border-bottom: 7px solid var(--brand-strong);
}

body.book-czyd .hero-band::before {
  content: "WORDS";
  position: absolute;
  right: 4vw;
  bottom: -24px;
  color: rgba(20, 122, 156, 0.08);
  font-family: Consolas, "Courier New", monospace;
  font-size: 92px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-czyd .hero-grid,
body.book-czyd .book-preview {
  position: relative;
  z-index: 1;
}

body.book-czyd .hero-grid p {
  color: #536d79;
}

body.book-czyd .hero-band .secondary-button,
body.book-czyd .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.9);
  border-color: rgba(20, 122, 156, 0.26);
}

body.book-czyd .book-preview {
  padding: 12px;
  border: 1px solid rgba(20, 122, 156, 0.26);
  border-top: 7px solid var(--accent);
  border-radius: 5px;
  background: #fff;
  box-shadow: 12px 12px 0 rgba(20, 122, 156, 0.1);
}

body.book-czyd .panel,
body.book-czyd .stat,
body.book-czyd .course-item,
body.book-czyd .practice-item,
body.book-czyd .paper-card,
body.book-czyd .question,
body.book-czyd .review-card,
body.book-czyd .history-row,
body.book-czyd .empty-state {
  border-color: rgba(20, 122, 156, 0.2);
}

body.book-czyd .stat {
  border-top: 4px solid var(--accent);
  background: linear-gradient(135deg, #ffffff, #eef8fc);
}

body.book-czyd .stat strong {
  color: var(--brand-strong);
}

body.book-czyd .course-item.active,
body.book-czyd .practice-item.active,
body.book-czyd .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(105deg, var(--brand-soft), var(--accent-soft));
}

body.book-gzsx {
  --ink: #20233b;
  --muted: #69708a;
  --line: #d8dced;
  --paper: #ffffff;
  --mist: #f6f7fc;
  --brand: #4a46a8;
  --brand-strong: #302d79;
  --brand-soft: #e8e7ff;
  --accent: #0f8b8d;
  --accent-soft: #dcf6f3;
  --blue: #456fd4;
  --blue-soft: #e6edff;
  --shadow: 0 16px 38px rgba(74, 70, 168, 0.13);
  --app-bg:
    linear-gradient(90deg, rgba(74, 70, 168, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, rgba(15, 139, 141, 0.05) 1px, transparent 1px),
    linear-gradient(180deg, #fdfdff 0%, #f2f3fc 58%, #ecfbf8 100%);
  background-size: 42px 42px, 42px 42px, auto;
}

body.book-gzsx .topbar {
  border-top: 4px solid var(--brand);
  border-bottom-color: rgba(74, 70, 168, 0.22);
  background: rgba(255, 255, 255, 0.96);
}

body.book-gzsx .brand-mark {
  border: 1px solid var(--brand-strong);
  border-radius: 4px;
  background: var(--brand-strong);
  color: #c9fff5;
  font-family: Consolas, "Courier New", monospace;
  box-shadow: 4px 4px 0 rgba(15, 139, 141, 0.2);
}

body.book-gzsx .nav a.active,
body.book-gzsx .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--accent);
}

body.book-gzsx .hero-band {
  color: var(--ink);
  background:
    linear-gradient(112deg, rgba(255, 255, 255, 0.98) 0 58%, rgba(232, 231, 255, 0.92) 58% 100%),
    repeating-linear-gradient(90deg, transparent 0 34px, rgba(74, 70, 168, 0.055) 34px 35px),
    #f7f7fd;
  border-bottom: 7px solid var(--brand-strong);
}

body.book-gzsx .hero-band::before {
  content: "MATH";
  position: absolute;
  right: 4vw;
  bottom: -24px;
  color: rgba(74, 70, 168, 0.08);
  font-family: Consolas, "Courier New", monospace;
  font-size: 108px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-gzsx .hero-grid,
body.book-gzsx .book-preview {
  position: relative;
  z-index: 1;
}

body.book-gzsx .hero-grid p {
  color: #5d6381;
}

body.book-gzsx .hero-band .secondary-button,
body.book-gzsx .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.9);
  border-color: rgba(74, 70, 168, 0.26);
}

body.book-gzsx .book-preview {
  padding: 12px;
  border: 1px solid rgba(74, 70, 168, 0.26);
  border-top: 7px solid var(--accent);
  border-radius: 5px;
  background: #fff;
  box-shadow: 12px 12px 0 rgba(74, 70, 168, 0.1);
}

body.book-gzsx .panel,
body.book-gzsx .stat,
body.book-gzsx .course-item,
body.book-gzsx .practice-item,
body.book-gzsx .paper-card,
body.book-gzsx .question,
body.book-gzsx .review-card,
body.book-gzsx .history-row,
body.book-gzsx .empty-state {
  border-color: rgba(74, 70, 168, 0.2);
}

body.book-gzsx .stat {
  border-top: 4px solid var(--accent);
  background: linear-gradient(135deg, #ffffff, #eef8f7);
}

body.book-gzsx .stat strong {
  color: var(--brand-strong);
}

body.book-gzsx .course-item.active,
body.book-gzsx .practice-item.active,
body.book-gzsx .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(105deg, var(--brand-soft), var(--accent-soft));
}

body.book-zjsx {
  --ink: #20261f;
  --muted: #6d756a;
  --line: #d8dbcf;
  --paper: #fffef8;
  --mist: #f3f3e8;
  --brand: #5b7f3a;
  --brand-strong: #344f26;
  --brand-soft: #e5efd9;
  --accent: #a75f2b;
  --accent-soft: #f8e4d3;
  --blue: #1d6f80;
  --blue-soft: #dff1ef;
  --shadow: 0 14px 32px rgba(64, 72, 53, 0.14);
  --app-bg:
    linear-gradient(135deg, rgba(52, 79, 38, 0.08), transparent 320px),
    repeating-linear-gradient(90deg, rgba(32, 38, 31, 0.045) 0 1px, transparent 1px 72px),
    #f3f3e8;
}

body.book-cet4 {
  --ink: #202b3d;
  --muted: #66738a;
  --line: #dbe3f1;
  --paper: #ffffff;
  --mist: #f7f9fe;
  --brand: #315fd6;
  --brand-strong: #2346a8;
  --brand-soft: #e6edff;
  --accent: #d84f6a;
  --accent-soft: #ffe7ec;
  --blue: #315fd6;
  --blue-soft: #e6edff;
  --shadow: 0 18px 42px rgba(49, 95, 214, 0.13);
  --app-bg:
    linear-gradient(180deg, rgba(49, 95, 214, 0.07), transparent 360px),
    repeating-linear-gradient(0deg, transparent 0 31px, rgba(49, 95, 214, 0.06) 31px 32px),
    #f8fbff;
}

body.book-ncre {
  --ink: #172028;
  --muted: #61717c;
  --line: #d4e1e3;
  --paper: #fbfeff;
  --mist: #eef7f7;
  --brand: #087f8c;
  --brand-strong: #075b63;
  --brand-soft: #dff7f9;
  --accent: #6a5acd;
  --accent-soft: #ece8ff;
  --blue: #087f8c;
  --blue-soft: #dff7f9;
  --shadow: 0 16px 38px rgba(8, 127, 140, 0.12);
  --app-bg:
    radial-gradient(circle at 85% 0%, rgba(106, 90, 205, 0.12), transparent 26rem),
    linear-gradient(90deg, rgba(8, 127, 140, 0.06) 1px, transparent 1px),
    linear-gradient(180deg, rgba(8, 127, 140, 0.05) 1px, transparent 1px),
    #f4fbfb;
  background-size: auto, 48px 48px, 48px 48px, auto;
}

body.book-cpa {
  --ink: #202225;
  --muted: #666b73;
  --line: #d6d2ca;
  --paper: #ffffff;
  --mist: #f5f6f7;
  --brand: #8a2635;
  --brand-strong: #5d1825;
  --brand-soft: #f7e8eb;
  --accent: #b7892f;
  --accent-soft: #fff4d8;
  --blue: #176b78;
  --blue-soft: #e2f2f3;
  --shadow: 0 12px 30px rgba(32, 34, 37, 0.11);
  --radius: 4px;
  --app-bg:
    repeating-linear-gradient(0deg, transparent 0 39px, rgba(32, 34, 37, 0.045) 39px 40px),
    linear-gradient(90deg, #f8f9fa 0 72%, #f1f4f3 72% 100%);
}

body.book-jkgl {
  --ink: #17332d;
  --muted: #5e716b;
  --line: #d2e3de;
  --paper: #ffffff;
  --mist: #f1f8f6;
  --brand: #168067;
  --brand-strong: #0e5948;
  --brand-soft: #dff5ed;
  --accent: #d65d55;
  --accent-soft: #ffe9e5;
  --blue: #2477a6;
  --blue-soft: #e3f2fa;
  --shadow: 0 16px 36px rgba(22, 128, 103, 0.11);
  --app-bg:
    linear-gradient(90deg, rgba(36, 119, 166, 0.045) 1px, transparent 1px),
    linear-gradient(180deg, rgba(22, 128, 103, 0.045) 1px, transparent 1px),
    #f5faf8;
  background-size: 56px 56px, 56px 56px, auto;
}

body.book-flzg {
  --ink: #2b2320;
  --muted: #6f625b;
  --line: #d9cec0;
  --paper: #fffdf8;
  --mist: #f5f0e7;
  --brand: #8f2634;
  --brand-strong: #5a1721;
  --brand-soft: #f8e8e9;
  --accent: #a77a28;
  --accent-soft: #fff2d4;
  --blue: #3d6170;
  --blue-soft: #e8f0f2;
  --shadow: 0 10px 26px rgba(63, 39, 31, 0.1);
  --radius: 3px;
  --app-bg:
    repeating-linear-gradient(0deg, transparent 0 35px, rgba(75, 51, 38, 0.045) 35px 36px),
    #f8f4ec;
}

body.book-gai {
  --ink: #16262a;
  --muted: #5a6d70;
  --line: #cadcdd;
  --paper: #ffffff;
  --mist: #f1f7f6;
  --brand: #087f8c;
  --brand-strong: #075861;
  --brand-soft: #dff5f4;
  --accent: #8cab18;
  --accent-soft: #f0f8d6;
  --blue: #176f9b;
  --blue-soft: #e4f3fa;
  --shadow: 0 14px 32px rgba(8, 127, 140, 0.12);
  --radius: 6px;
  --app-bg:
    linear-gradient(90deg, rgba(8, 127, 140, 0.055) 1px, transparent 1px),
    linear-gradient(180deg, rgba(8, 127, 140, 0.055) 1px, transparent 1px),
    #f4f9f8;
  background-size: 44px 44px, 44px 44px, auto;
}

body.book-rgznxls {
  --ink: #102b2e;
  --muted: #5d7474;
  --line: #c9ded8;
  --paper: #fcfffd;
  --mist: #edf7f4;
  --brand: #0b7285;
  --brand-strong: #075985;
  --brand-soft: #d8f2ec;
  --accent: #e4862d;
  --accent-soft: #fff0d8;
  --blue: #3d8ea3;
  --blue-soft: #dceff3;
  --shadow: 0 14px 34px rgba(10, 77, 83, 0.13);
  --radius: 5px;
  --app-bg:
    linear-gradient(90deg, rgba(11, 114, 133, 0.065) 1px, transparent 1px),
    linear-gradient(180deg, rgba(11, 114, 133, 0.065) 1px, transparent 1px),
    #f2faf7;
  background-size: 32px 32px, 32px 32px, auto;
}

body.book-gwy {
  --ink: #292d35;
  --muted: #6d7078;
  --line: #d8d1c5;
  --paper: #fffdf8;
  --mist: #f4f0e8;
  --brand: #a33a34;
  --brand-strong: #762621;
  --brand-soft: #f5dedb;
  --accent: #bd873c;
  --accent-soft: #fff0d5;
  --blue: #365d80;
  --blue-soft: #e1ecf5;
  --shadow: 0 12px 28px rgba(54, 42, 32, 0.12);
  --radius: 2px;
  --app-bg:
    repeating-linear-gradient(0deg, transparent 0 37px, rgba(74, 54, 36, 0.045) 37px 38px),
    linear-gradient(90deg, #fbf8f1 0 72%, #f0eee8 72% 100%);
}

body.book-psc {
  --ink: #2f2925;
  --muted: #746a62;
  --line: #e4d9cd;
  --paper: #fffdf8;
  --mist: #faf4eb;
  --brand: #c74235;
  --brand-strong: #932c24;
  --brand-soft: #fbe4df;
  --accent: #257b70;
  --accent-soft: #e1f3ed;
  --blue: #416d92;
  --blue-soft: #e9f1f8;
  --shadow: 0 18px 42px rgba(91, 52, 36, 0.12);
  --radius: 18px;
  --app-bg:
    radial-gradient(circle at 92% 7%, rgba(199, 66, 53, 0.12), transparent 22rem),
    repeating-linear-gradient(0deg, transparent 0 31px, rgba(92, 68, 55, 0.04) 31px 32px),
    #fbf6ee;
}

body.book-xfgcs {
  --ink: #142637;
  --muted: #607180;
  --line: #cbd8df;
  --paper: #fbfdfe;
  --mist: #edf3f5;
  --brand: #e45432;
  --brand-strong: #b4371d;
  --brand-soft: #ffe5dc;
  --accent: #c89a31;
  --accent-soft: #fff0c8;
  --blue: #155878;
  --blue-soft: #dceef4;
  --shadow: 0 16px 36px rgba(13, 43, 62, 0.14);
  --radius: 4px;
  --app-bg:
    linear-gradient(90deg, rgba(21, 88, 120, 0.055) 1px, transparent 1px),
    linear-gradient(180deg, rgba(21, 88, 120, 0.055) 1px, transparent 1px),
    #eef4f6;
  background-size: 28px 28px, 28px 28px, auto;
}

button,
input,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible {
  outline: 3px solid rgba(49, 95, 214, 0.28);
  outline-offset: 2px;
}

a {
  color: inherit;
  text-decoration: none;
}

.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 18px;
  padding: 14px max(18px, calc((100vw - 1180px) / 2));
  border-bottom: 1px solid rgba(215, 222, 232, 0.9);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 210px;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--brand), #1d9c89);
  color: #fff;
  font-weight: 800;
  font-size: 13px;
}

.brand strong,
.brand small {
  display: block;
  line-height: 1.15;
}

.brand strong {
  font-size: 17px;
}

.brand small {
  margin-top: 4px;
  color: var(--muted);
  font-size: 12px;
}

.nav {
  display: flex;
  justify-content: center;
  gap: 6px;
  min-width: 0;
}

.nav a {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  padding: 0 13px;
  border-radius: 8px;
  color: var(--muted);
  font-weight: 650;
  white-space: nowrap;
}

.nav a:hover,
.nav a.active {
  color: var(--brand-strong);
  background: var(--brand-soft);
}

.top-actions {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 9px;
  min-width: 168px;
}

.main {
  flex: 1;
  width: 100%;
}

.section {
  width: var(--content);
  margin: 0 auto;
  padding: 30px 0;
}

.hero-band {
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(125deg, #12312e 0%, #0f766e 56%, #1f4ba8 100%),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.08) 0 1px, transparent 1px 74px);
  color: #fff;
  border-bottom: 1px solid rgba(255, 255, 255, 0.18);
}

.hero-grid {
  width: var(--content);
  margin: 0 auto;
  padding: 42px 0;
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(360px, 0.55fr);
  gap: 34px;
  align-items: center;
}

.hero-grid h1 {
  margin: 10px 0 14px;
  font-size: clamp(34px, 4.6vw, 58px);
  line-height: 1.05;
  letter-spacing: 0;
}

.hero-grid p {
  max-width: 700px;
  margin: 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: 17px;
  line-height: 1.75;
}

.hero-actions,
.row-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.hero-actions {
  margin-top: 20px;
}

.hero-band .secondary-button,
.hero-band .ghost-button {
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.54);
  backdrop-filter: blur(10px);
}

.hero-band .secondary-button:hover,
.hero-band .ghost-button:hover {
  background: rgba(255, 255, 255, 0.18);
}

.book-preview {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.book-preview img {
  width: 100%;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: 8px;
  box-shadow: 0 16px 38px rgba(0, 0, 0, 0.22);
  background: #e5e7eb;
}

body.book-czsx .topbar {
  background: rgba(255, 255, 255, 0.9);
  border-bottom-color: rgba(21, 143, 139, 0.2);
}

body.book-czsx .brand-mark {
  background: #fff;
  color: var(--brand-strong);
  border: 2px solid var(--brand);
  box-shadow: inset 0 -5px 0 rgba(255, 240, 199, 0.9);
}

body.book-czsx .nav a.active,
body.book-czsx .nav a:hover {
  color: var(--brand-strong);
  background: linear-gradient(180deg, #efffff, var(--brand-soft));
}

body.book-czsx .hero-band {
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(47, 111, 228, 0.09) 1px, transparent 1px),
    linear-gradient(180deg, rgba(21, 143, 139, 0.09) 1px, transparent 1px),
    linear-gradient(135deg, #ffffff 0%, #eafcff 58%, #fff2c2 100%);
  background-size: 42px 42px, 42px 42px, auto;
  border-bottom-color: rgba(21, 143, 139, 0.18);
}

body.book-czsx .hero-band::before {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 10px;
  background: repeating-linear-gradient(90deg, #158f8b 0 42px, #2f6fe4 42px 84px, #d97706 84px 126px);
}

body.book-czsx .hero-grid p {
  color: #475569;
}

body.book-czsx .hero-band .secondary-button,
body.book-czsx .hero-band .ghost-button,
body.book-cet4 .hero-band .secondary-button,
body.book-cet4 .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.72);
  border-color: rgba(49, 95, 214, 0.18);
}

body.book-czsx .hero-band .eyebrow {
  color: var(--brand-strong);
}

body.book-czsx .book-preview {
  align-items: center;
  transform: rotate(-1.2deg);
}

body.book-czsx .book-preview img {
  border: 6px solid #fff;
  box-shadow: 0 16px 34px rgba(31, 80, 122, 0.18);
}

body.book-czsx .book-preview img:nth-child(2),
body.book-czsx .book-preview img:nth-child(3) {
  transform: translateY(18px) rotate(3deg);
}

body.book-czsx .stat,
body.book-czsx .panel,
body.book-czsx .course-item,
body.book-czsx .practice-item,
body.book-czsx .paper-card,
body.book-czsx .lesson-section,
body.book-czsx .question,
body.book-czsx .review-card,
body.book-czsx .history-row,
body.book-czsx .empty-state {
  border-color: rgba(47, 111, 228, 0.14);
}

body.book-czsx .stat {
  background: linear-gradient(180deg, #fff, #f1fbff);
  box-shadow: 0 10px 24px rgba(47, 111, 228, 0.08);
}

body.book-czsx .stat strong {
  color: var(--brand-strong);
}

body.book-czsx .course-item.active,
body.book-czsx .practice-item.active,
body.book-czsx .paper-card.active {
  background: linear-gradient(135deg, #e6fffb, #fff7dc);
}

body.book-zjsx .topbar {
  background: rgba(36, 43, 32, 0.96);
  border-bottom-color: rgba(255, 255, 255, 0.12);
}

body.book-zjsx .brand strong,
body.book-zjsx .nav a {
  color: #f7f6ed;
}

body.book-zjsx .brand small {
  color: rgba(247, 246, 237, 0.66);
}

body.book-zjsx .brand-mark {
  background: linear-gradient(135deg, #a75f2b, #5b7f3a);
  color: #fffef8;
}

body.book-zjsx .nav a:hover,
body.book-zjsx .nav a.active {
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
}

body.book-zjsx .topbar .secondary-button {
  color: #fffef8;
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.22);
}

body.book-zjsx .hero-band {
  background:
    linear-gradient(135deg, #24301f 0%, #526c34 52%, #a75f2b 100%),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.08) 0 1px, transparent 1px 68px);
  border-bottom-color: rgba(255, 255, 255, 0.2);
}

body.book-zjsx .hero-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(120deg, transparent 0 58%, rgba(255, 255, 255, 0.08) 58% 64%, transparent 64%),
    repeating-linear-gradient(0deg, transparent 0 38px, rgba(255, 255, 255, 0.05) 38px 39px);
  pointer-events: none;
}

body.book-zjsx .hero-grid {
  position: relative;
  z-index: 1;
  grid-template-columns: minmax(0, 0.82fr) minmax(340px, 0.48fr);
}

body.book-zjsx .book-preview {
  position: relative;
  display: block;
  min-height: 340px;
  padding: 18px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 8px;
  background: rgba(255, 254, 248, 0.12);
  box-shadow: 0 22px 48px rgba(32, 38, 31, 0.24);
}

body.book-zjsx .book-preview img {
  display: none;
}

body.book-zjsx .book-preview img:first-child {
  display: block;
  width: 74%;
  margin-left: auto;
  border: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 18px 38px rgba(0, 0, 0, 0.26);
}

body.book-zjsx .book-preview::before,
body.book-zjsx .book-preview::after {
  content: "";
  position: absolute;
  left: 18px;
  right: 42%;
  border-radius: 8px;
  background: rgba(255, 254, 248, 0.18);
}

body.book-zjsx .book-preview::before {
  top: 34px;
  height: 118px;
  box-shadow: 0 138px 0 rgba(255, 254, 248, 0.12);
}

body.book-zjsx .book-preview::after {
  top: 62px;
  height: 12px;
  background: #f3bd7a;
  box-shadow:
    0 28px 0 rgba(255, 254, 248, 0.5),
    0 56px 0 rgba(255, 254, 248, 0.32),
    0 138px 0 #9fbc6b,
    0 166px 0 rgba(255, 254, 248, 0.36);
}

body.book-zjsx .panel,
body.book-zjsx .stat,
body.book-zjsx .course-item,
body.book-zjsx .practice-item,
body.book-zjsx .paper-card,
body.book-zjsx .question,
body.book-zjsx .review-card,
body.book-zjsx .history-row,
body.book-zjsx .empty-state {
  border-color: var(--line);
  box-shadow: none;
}

body.book-zjsx .panel {
  border-top: 4px solid var(--brand);
}

body.book-zjsx .stat {
  position: relative;
  min-height: 104px;
  padding-left: 20px;
  background: #fffef8;
}

body.book-zjsx .stat::before {
  content: "";
  position: absolute;
  inset: 18px auto 18px 0;
  width: 4px;
  background: var(--accent);
}

body.book-zjsx .stat strong {
  color: #344f26;
  font-size: 28px;
}

body.book-zjsx .course-item,
body.book-zjsx .practice-item,
body.book-zjsx .paper-card {
  background: #fffef8;
}

body.book-zjsx .course-item.active,
body.book-zjsx .practice-item.active,
body.book-zjsx .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(90deg, #eef5e5, #fff9ef);
}

body.book-cet4 .topbar {
  background: rgba(255, 255, 255, 0.94);
  border-bottom-color: rgba(49, 95, 214, 0.16);
}

body.book-cet4 .brand-mark {
  background: linear-gradient(135deg, #315fd6, #d84f6a);
}

body.book-cet4 .nav a.active,
body.book-cet4 .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
}

body.book-cet4 .hero-band {
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(49, 95, 214, 0.08) 0 1px, transparent 1px 54px),
    linear-gradient(180deg, #ffffff 0%, #eef4ff 58%, #fff2f5 100%);
  border-bottom-color: rgba(49, 95, 214, 0.18);
}

body.book-cet4 .hero-band::before {
  content: "A  B  C  D";
  position: absolute;
  right: 6vw;
  top: 24px;
  color: rgba(49, 95, 214, 0.08);
  font-size: clamp(74px, 12vw, 170px);
  font-weight: 900;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-cet4 .hero-band .eyebrow {
  color: var(--accent);
}

body.book-cet4 .hero-grid p {
  color: #40506a;
}

body.book-cet4 .book-preview {
  position: relative;
  transform: none;
}

body.book-cet4 .book-preview img {
  border: 1px solid rgba(49, 95, 214, 0.18);
  box-shadow: 0 16px 34px rgba(49, 95, 214, 0.16);
}

body.book-cet4 .book-preview img:nth-child(1) {
  transform: rotate(-2deg);
}

body.book-cet4 .book-preview img:nth-child(2) {
  transform: translateY(20px) rotate(1.5deg);
}

body.book-cet4 .book-preview img:nth-child(3) {
  transform: translateY(-10px) rotate(2deg);
}

body.book-cet4 .book-preview img:nth-child(4) {
  transform: translateY(16px) rotate(-1deg);
}

body.book-cet4 .panel {
  border-top: 3px solid var(--accent);
}

body.book-cet4 .stat {
  background: linear-gradient(180deg, #fff, #f4f7ff);
}

body.book-cet4 .stat strong {
  color: var(--brand-strong);
}

body.book-cet4 .course-item.active,
body.book-cet4 .practice-item.active,
body.book-cet4 .paper-card.active {
  border-color: rgba(216, 79, 106, 0.46);
  background: linear-gradient(135deg, #eef4ff, #fff0f4);
}

body.book-ncre .topbar {
  background: rgba(251, 254, 255, 0.92);
  border-bottom-color: rgba(8, 127, 140, 0.2);
}

body.book-ncre .brand-mark {
  background: #172028;
  color: #78f2ff;
  font-family: Consolas, "Courier New", monospace;
}

body.book-ncre .nav a.active,
body.book-ncre .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
}

body.book-ncre .hero-band {
  background:
    radial-gradient(circle at 74% 22%, rgba(120, 242, 255, 0.26), transparent 18rem),
    linear-gradient(135deg, #172028 0%, #075b63 56%, #2b266e 100%);
  border-bottom-color: rgba(120, 242, 255, 0.24);
}

body.book-ncre .hero-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(120, 242, 255, 0.07) 1px, transparent 1px),
    linear-gradient(180deg, rgba(120, 242, 255, 0.07) 1px, transparent 1px);
  background-size: 42px 42px;
  pointer-events: none;
}

body.book-ncre .hero-grid {
  position: relative;
  z-index: 1;
}

body.book-ncre .book-preview {
  padding: 16px;
  border: 1px solid rgba(120, 242, 255, 0.24);
  border-radius: 8px;
  background: rgba(23, 32, 40, 0.42);
  box-shadow: 0 22px 48px rgba(0, 0, 0, 0.24);
}

body.book-ncre .book-preview img {
  border: 1px solid rgba(120, 242, 255, 0.26);
  box-shadow: none;
  filter: saturate(0.95);
}

body.book-ncre .book-preview img:nth-child(2),
body.book-ncre .book-preview img:nth-child(4) {
  transform: translateY(18px);
}

body.book-ncre .panel,
body.book-ncre .stat,
body.book-ncre .course-item,
body.book-ncre .practice-item,
body.book-ncre .paper-card,
body.book-ncre .question,
body.book-ncre .review-card,
body.book-ncre .history-row,
body.book-ncre .empty-state {
  border-color: rgba(8, 127, 140, 0.18);
}

body.book-ncre .panel {
  box-shadow: 0 1px 0 rgba(8, 127, 140, 0.12), var(--shadow);
}

body.book-ncre .stat {
  background:
    linear-gradient(90deg, rgba(8, 127, 140, 0.11), transparent 38%),
    #fff;
}

body.book-ncre .stat strong {
  color: var(--brand-strong);
  font-family: Consolas, "Courier New", monospace;
}

body.book-ncre .course-item.active,
body.book-ncre .practice-item.active,
body.book-ncre .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(135deg, #e8fbfd, #f0edff);
}

body.book-cpa .topbar {
  border-top: 4px solid var(--brand);
  border-bottom: 3px double #b9b3aa;
  background: rgba(255, 255, 255, 0.96);
}

body.book-cpa .brand-mark {
  background: #202225;
  color: #f3d58f;
  font-family: Georgia, "Times New Roman", serif;
}

body.book-cpa .nav a.active,
body.book-cpa .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--brand);
}

body.book-cpa .hero-band {
  color: var(--ink);
  background:
    repeating-linear-gradient(0deg, transparent 0 43px, rgba(32, 34, 37, 0.065) 43px 44px),
    linear-gradient(100deg, #ffffff 0 62%, #eef5f4 62% 100%);
  border-bottom: 8px solid var(--brand);
}

body.book-cpa .hero-band::before {
  content: "CPA";
  position: absolute;
  right: 5vw;
  bottom: -36px;
  color: rgba(138, 38, 53, 0.07);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 180px;
  font-weight: 800;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-cpa .hero-grid,
body.book-jkgl .hero-grid {
  position: relative;
  z-index: 1;
}

body.book-cpa .hero-grid p {
  color: #565b63;
}

body.book-cpa .hero-band .eyebrow {
  color: var(--brand);
  letter-spacing: 0;
}

body.book-cpa .hero-band .secondary-button,
body.book-cpa .hero-band .ghost-button {
  color: var(--ink);
  background: #fff;
  border-color: #aaa49a;
}

body.book-cpa .book-preview {
  padding: 12px;
  border: 1px solid #b9b3aa;
  border-left: 7px solid var(--brand);
  background: #fff;
  box-shadow: 12px 12px 0 rgba(23, 107, 120, 0.1);
}

body.book-cpa .book-preview img {
  border: 1px solid #c8c2b9;
  border-radius: 2px;
  box-shadow: none;
}

body.book-cpa .panel,
body.book-cpa .stat,
body.book-cpa .course-item,
body.book-cpa .practice-item,
body.book-cpa .paper-card,
body.book-cpa .question,
body.book-cpa .review-card,
body.book-cpa .history-row,
body.book-cpa .empty-state {
  border-color: #d6d2ca;
}

body.book-cpa .stat {
  border-top: 4px solid var(--brand);
}

body.book-cpa .stat strong {
  color: var(--brand-strong);
  font-family: Georgia, "Times New Roman", serif;
}

body.book-cpa .course-item.active,
body.book-cpa .practice-item.active,
body.book-cpa .paper-card.active {
  border-color: var(--brand);
  border-left-width: 5px;
  background: linear-gradient(90deg, var(--brand-soft), #fff 72%);
}

body.book-jkgl .topbar {
  background: rgba(255, 255, 255, 0.95);
  border-bottom-color: rgba(22, 128, 103, 0.22);
}

body.book-jkgl .brand-mark {
  background: var(--brand);
  box-shadow: inset 0 0 0 5px rgba(255, 255, 255, 0.16);
}

body.book-jkgl .nav a.active,
body.book-jkgl .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
}

body.book-jkgl .hero-band {
  color: var(--ink);
  background:
    linear-gradient(90deg, transparent 0 74%, rgba(36, 119, 166, 0.08) 74% 100%),
    linear-gradient(180deg, #ffffff 0%, #edf9f5 100%);
  border-bottom: 1px solid rgba(22, 128, 103, 0.2);
}

body.book-jkgl .hero-band::before {
  content: "+";
  position: absolute;
  right: 8vw;
  top: -76px;
  color: rgba(214, 93, 85, 0.1);
  font-size: 280px;
  font-weight: 300;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-jkgl .hero-grid p {
  color: #4f6861;
}

body.book-jkgl .hero-band .eyebrow {
  color: var(--accent);
  letter-spacing: 0;
}

body.book-jkgl .hero-band .secondary-button,
body.book-jkgl .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.88);
  border-color: rgba(22, 128, 103, 0.28);
}

body.book-jkgl .book-preview {
  gap: 8px;
  padding: 10px;
  border: 1px solid rgba(22, 128, 103, 0.2);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 18px 34px rgba(22, 128, 103, 0.13);
}

body.book-jkgl .book-preview img {
  border: 1px solid #d2e3de;
  box-shadow: none;
}

body.book-jkgl .book-preview img:nth-child(1),
body.book-jkgl .book-preview img:nth-child(4) {
  transform: translateY(10px);
}

body.book-jkgl .panel,
body.book-jkgl .stat,
body.book-jkgl .course-item,
body.book-jkgl .practice-item,
body.book-jkgl .paper-card,
body.book-jkgl .question,
body.book-jkgl .review-card,
body.book-jkgl .history-row,
body.book-jkgl .empty-state {
  border-color: rgba(22, 128, 103, 0.2);
}

body.book-jkgl .stat {
  background: linear-gradient(135deg, #ffffff, #edf9f5);
}

body.book-jkgl .stat strong {
  color: var(--brand-strong);
}

body.book-jkgl .course-item.active,
body.book-jkgl .practice-item.active,
body.book-jkgl .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(110deg, var(--brand-soft), var(--blue-soft));
}

body.book-flzg .topbar {
  border-top: 4px solid var(--brand);
  border-bottom: 3px double #b9aa98;
  background: rgba(255, 253, 248, 0.97);
}

body.book-flzg .brand-mark {
  border: 2px solid #f0d9b0;
  border-radius: 50%;
  background: var(--brand);
  color: #fff8e8;
  box-shadow: inset 0 0 0 3px rgba(255, 255, 255, 0.18);
  font-family: "STKaiti", "KaiTi", serif;
}

body.book-flzg .nav a.active,
body.book-flzg .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--brand);
}

body.book-flzg .hero-band {
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(255, 253, 248, 0.98) 0 67%, rgba(167, 122, 40, 0.09) 67% 100%),
    repeating-linear-gradient(0deg, transparent 0 41px, rgba(75, 51, 38, 0.06) 41px 42px),
    #fffdf8;
  border-bottom: 7px solid var(--brand);
}

body.book-flzg .hero-band::before {
  content: "法";
  position: absolute;
  right: 7vw;
  top: -56px;
  color: rgba(143, 38, 52, 0.08);
  font-family: "STKaiti", "KaiTi", serif;
  font-size: 260px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-flzg .hero-grid,
body.book-gai .hero-grid {
  position: relative;
  z-index: 1;
}

body.book-flzg .hero-grid p {
  color: #66574f;
}

body.book-flzg .book-preview {
  padding: 12px;
  border: 3px double #b9aa98;
  border-left: 8px solid var(--brand);
  border-radius: 2px;
  background: #fffdf8;
  box-shadow: 10px 10px 0 rgba(167, 122, 40, 0.12);
}

body.book-flzg .panel,
body.book-flzg .stat,
body.book-flzg .course-item,
body.book-flzg .practice-item,
body.book-flzg .paper-card,
body.book-flzg .question,
body.book-flzg .review-card,
body.book-flzg .history-row,
body.book-flzg .empty-state {
  border-color: #d9cec0;
}

body.book-flzg .course-item.active,
body.book-flzg .practice-item.active,
body.book-flzg .paper-card.active {
  border-color: var(--brand);
  border-left-width: 6px;
  background: linear-gradient(90deg, var(--brand-soft), #fffdf8 76%);
}

body.book-gai .topbar {
  border-top: 4px solid #b6d53b;
  border-bottom-color: rgba(8, 127, 140, 0.25);
  background: rgba(250, 253, 252, 0.96);
}

body.book-gai .brand-mark {
  border: 1px solid #0f2f34;
  border-radius: 6px;
  background: #16363b;
  color: #d7f35e;
  box-shadow: 4px 4px 0 rgba(8, 127, 140, 0.18);
}

body.book-gai .nav a.active,
body.book-gai .nav a:hover {
  color: #0d4e56;
  background: #e4f5f3;
  box-shadow: inset 0 -3px 0 #9dbb21;
}

body.book-gai .hero-band {
  color: var(--ink);
  background:
    linear-gradient(120deg, rgba(255, 255, 255, 0.98) 0 64%, rgba(215, 243, 94, 0.17) 64% 100%),
    linear-gradient(90deg, rgba(8, 127, 140, 0.07) 1px, transparent 1px),
    linear-gradient(180deg, rgba(8, 127, 140, 0.07) 1px, transparent 1px),
    #f4faf8;
  background-size: auto, 36px 36px, 36px 36px, auto;
  border-bottom: 7px solid #16363b;
}

body.book-gai .hero-band::before {
  content: "</>";
  position: absolute;
  right: 4vw;
  bottom: -12px;
  color: rgba(8, 127, 140, 0.09);
  font-family: Consolas, "Courier New", monospace;
  font-size: 130px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-gai .hero-grid p {
  color: #4f6669;
}

body.book-gai .hero-band .eyebrow {
  color: #668313;
}

body.book-gai .book-preview {
  padding: 10px;
  border: 1px solid rgba(8, 127, 140, 0.28);
  border-top: 7px solid #b6d53b;
  border-radius: 6px;
  background: #fff;
  box-shadow: 12px 12px 0 rgba(8, 127, 140, 0.1);
}

body.book-gai .primary-button {
  border-color: #16363b;
  background: #16363b;
  color: #efffb2;
}

body.book-gai .panel,
body.book-gai .stat,
body.book-gai .course-item,
body.book-gai .practice-item,
body.book-gai .paper-card,
body.book-gai .question,
body.book-gai .review-card,
body.book-gai .history-row,
body.book-gai .empty-state {
  border-color: rgba(8, 127, 140, 0.22);
}

body.book-gai .stat {
  border-top: 4px solid #b6d53b;
  background: linear-gradient(135deg, #ffffff, #eef8f6);
}

body.book-gai .course-item.active,
body.book-gai .practice-item.active,
body.book-gai .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(105deg, var(--brand-soft), var(--accent-soft));
}

body.book-rgznxls .topbar {
  border-top: 4px solid var(--accent);
  border-bottom-color: rgba(11, 114, 133, 0.28);
  background: rgba(250, 255, 253, 0.96);
}

body.book-rgznxls .brand-mark {
  border: 1px solid #0b4650;
  border-radius: 4px;
  background: #0b4650;
  color: #ffd99b;
  box-shadow: 4px 4px 0 rgba(228, 134, 45, 0.2);
  font-family: Consolas, "Courier New", monospace;
}

body.book-rgznxls .nav a.active,
body.book-rgznxls .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--accent);
}

body.book-rgznxls .hero-band {
  color: var(--ink);
  background:
    linear-gradient(115deg, rgba(255, 255, 255, 0.98) 0 62%, rgba(255, 240, 216, 0.92) 62% 100%),
    linear-gradient(90deg, rgba(11, 114, 133, 0.08) 1px, transparent 1px),
    linear-gradient(180deg, rgba(11, 114, 133, 0.08) 1px, transparent 1px),
    #f2faf7;
  background-size: auto, 34px 34px, 34px 34px, auto;
  border-bottom: 7px solid #0b4650;
}

body.book-rgznxls .hero-band::before {
  content: "AI";
  position: absolute;
  right: 5vw;
  bottom: -26px;
  color: rgba(11, 114, 133, 0.09);
  font-family: Consolas, "Courier New", monospace;
  font-size: 170px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-rgznxls .hero-grid,
body.book-rgznxls .book-preview {
  position: relative;
  z-index: 1;
}

body.book-rgznxls .hero-grid p {
  color: #506a6c;
}

body.book-rgznxls .hero-band .secondary-button,
body.book-rgznxls .hero-band .ghost-button,
body.book-gwy .hero-band .secondary-button,
body.book-gwy .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.86);
  border-color: rgba(11, 114, 133, 0.26);
}

body.book-gwy .hero-band .secondary-button,
body.book-gwy .hero-band .ghost-button {
  border-color: rgba(163, 58, 52, 0.28);
}

body.book-rgznxls .book-preview {
  padding: 12px;
  border: 1px solid rgba(11, 114, 133, 0.3);
  border-top: 7px solid var(--accent);
  border-radius: 5px;
  background: #ffffff;
  box-shadow: 12px 12px 0 rgba(11, 114, 133, 0.11);
}

body.book-rgznxls .panel,
body.book-rgznxls .stat,
body.book-rgznxls .course-item,
body.book-rgznxls .practice-item,
body.book-rgznxls .paper-card,
body.book-rgznxls .question,
body.book-rgznxls .review-card,
body.book-rgznxls .history-row,
body.book-rgznxls .empty-state {
  border-color: rgba(11, 114, 133, 0.23);
}

body.book-rgznxls .stat {
  border-top: 4px solid var(--accent);
  background: linear-gradient(135deg, #ffffff, #eef8f5);
}

body.book-rgznxls .course-item.active,
body.book-rgznxls .practice-item.active,
body.book-rgznxls .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(105deg, var(--brand-soft), var(--accent-soft));
}

body.book-ccpt {
  --ink: #28221f;
  --muted: #756963;
  --line: #d9cfc5;
  --paper: #fffdf8;
  --mist: #f4efe8;
  --brand: #a53e32;
  --brand-strong: #71261f;
  --brand-soft: #f9e5dc;
  --accent: #b7822b;
  --accent-soft: #fff1ce;
  --blue: #2d6f72;
  --blue-soft: #e2f1ef;
  --shadow: 0 14px 34px rgba(74, 47, 35, 0.12);
  --app-bg:
    repeating-linear-gradient(0deg, transparent 0 35px, rgba(92, 66, 50, 0.045) 35px 36px),
    linear-gradient(180deg, #fffdf8 0%, #f8f0e6 62%, #edf4f0 100%);
  background-size: auto;
}

body.book-ccpt .topbar {
  border-top: 4px solid var(--brand);
  border-bottom-color: rgba(165, 62, 50, 0.2);
  background: rgba(255, 253, 248, 0.96);
}

body.book-ccpt .brand-mark {
  border: 1px solid #70251f;
  border-radius: 50%;
  background: #70251f;
  color: #fff2cf;
  font-family: "STKaiti", "KaiTi", serif;
  box-shadow: inset 0 0 0 4px rgba(255, 241, 206, 0.18);
}

body.book-ccpt .nav a.active,
body.book-ccpt .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--accent);
}

body.book-ccpt .hero-band {
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(255, 253, 248, 0.98) 0 61%, rgba(249, 229, 220, 0.82) 61% 100%),
    repeating-linear-gradient(0deg, transparent 0 38px, rgba(112, 37, 31, 0.06) 38px 39px),
    #fffdf8;
  border-bottom: 7px solid var(--brand);
}

body.book-ccpt .hero-band::before {
  content: "書畫";
  position: absolute;
  right: 4vw;
  bottom: -30px;
  color: rgba(165, 62, 50, 0.09);
  font-family: "STKaiti", "KaiTi", serif;
  font-size: 150px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-ccpt .hero-grid,
body.book-ccpt .book-preview {
  position: relative;
  z-index: 1;
}

body.book-ccpt .hero-grid p {
  color: #665650;
}

body.book-ccpt .hero-band .secondary-button,
body.book-ccpt .hero-band .ghost-button {
  color: var(--ink);
  background: rgba(255, 253, 248, 0.9);
  border-color: rgba(165, 62, 50, 0.3);
}

body.book-ccpt .book-preview {
  padding: 12px;
  border: 3px double #bda694;
  border-left: 8px solid var(--brand);
  border-radius: 2px;
  background: #fffdf8;
  box-shadow: 10px 10px 0 rgba(183, 130, 43, 0.13);
}

body.book-ccpt .book-preview img {
  border: 1px solid #d9cfc5;
  border-radius: 2px;
  box-shadow: none;
}

body.book-ccpt .book-preview img:nth-child(2),
body.book-ccpt .book-preview img:nth-child(4) {
  transform: translateY(12px);
}

body.book-ccpt .panel,
body.book-ccpt .stat,
body.book-ccpt .course-item,
body.book-ccpt .practice-item,
body.book-ccpt .paper-card,
body.book-ccpt .question,
body.book-ccpt .review-card,
body.book-ccpt .history-row,
body.book-ccpt .empty-state {
  border-color: #d9cfc5;
}

body.book-ccpt .stat {
  border-top: 4px solid var(--brand);
  background: linear-gradient(135deg, #fffdf8, #f8eee3);
}

body.book-ccpt .stat strong {
  color: var(--brand-strong);
  font-family: "STKaiti", "KaiTi", serif;
}

body.book-ccpt .course-item.active,
body.book-ccpt .practice-item.active,
body.book-ccpt .paper-card.active {
  border-color: var(--brand);
  border-left-width: 5px;
  background: linear-gradient(90deg, var(--brand-soft), #fffdf8 76%);
}

body.book-gwy .topbar {
  border-top: 4px solid var(--brand);
  border-bottom: 3px double #c9bcae;
  background: rgba(255, 253, 248, 0.97);
}

body.book-gwy .brand-mark {
  border: 2px solid #e2c487;
  border-radius: 50%;
  background: var(--brand);
  color: #fff8e8;
  box-shadow: inset 0 0 0 3px rgba(255, 255, 255, 0.17);
  font-family: "STKaiti", "KaiTi", serif;
}

body.book-gwy .nav a.active,
body.book-gwy .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--brand);
}

body.book-gwy .hero-band {
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(255, 253, 248, 0.98) 0 68%, rgba(189, 135, 60, 0.12) 68% 100%),
    repeating-linear-gradient(0deg, transparent 0 41px, rgba(74, 54, 36, 0.06) 41px 42px),
    #fffdf8;
  border-bottom: 7px solid var(--brand);
}

body.book-gwy .hero-band::before {
  content: "面";
  position: absolute;
  right: 7vw;
  top: -52px;
  color: rgba(163, 58, 52, 0.08);
  font-family: "STKaiti", "KaiTi", serif;
  font-size: 260px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0;
  pointer-events: none;
}

body.book-gwy .hero-grid,
body.book-gwy .book-preview {
  position: relative;
  z-index: 1;
}

body.book-gwy .hero-grid p {
  color: #6a625a;
}

body.book-gwy .book-preview {
  padding: 12px;
  border: 3px double #c9bcae;
  border-right: 8px solid var(--brand);
  border-radius: 2px;
  background: #fffdf8;
  box-shadow: -10px 10px 0 rgba(189, 135, 60, 0.13);
}

body.book-gwy .panel,
body.book-gwy .stat,
body.book-gwy .course-item,
body.book-gwy .practice-item,
body.book-gwy .paper-card,
body.book-gwy .question,
body.book-gwy .review-card,
body.book-gwy .history-row,
body.book-gwy .empty-state {
  border-color: #d8d1c5;
}

body.book-gwy .course-item.active,
body.book-gwy .practice-item.active,
body.book-gwy .paper-card.active {
  border-color: var(--brand);
  border-left-width: 6px;
  background: linear-gradient(90deg, var(--brand-soft), #fffdf8 76%);
}

body.book-psc .topbar {
  border-bottom: 1px solid rgba(147, 44, 36, 0.2);
  background: rgba(255, 253, 248, 0.94);
}

body.book-psc .brand-mark {
  border: 2px solid var(--brand);
  border-radius: 50%;
  color: var(--brand-strong);
  background:
    linear-gradient(90deg, transparent 18%, currentColor 18% 22%, transparent 22% 34%, currentColor 34% 40%, transparent 40% 52%, currentColor 52% 60%, transparent 60% 72%, currentColor 72% 76%, transparent 76%),
    #fff8f1;
  box-shadow: 0 5px 0 rgba(199, 66, 53, 0.12);
  font-size: 0;
}

body.book-psc .nav a.active,
body.book-psc .nav a:hover {
  color: var(--brand-strong);
  background: var(--brand-soft);
  box-shadow: inset 0 -3px 0 var(--brand);
}

body.book-psc .hero-band {
  color: var(--ink);
  border-bottom: 8px double rgba(147, 44, 36, 0.72);
  background:
    radial-gradient(circle at 12% 20%, rgba(199, 66, 53, 0.12), transparent 18rem),
    radial-gradient(circle at 88% 70%, rgba(37, 123, 112, 0.12), transparent 21rem),
    repeating-linear-gradient(0deg, transparent 0 35px, rgba(74, 50, 37, 0.05) 35px 36px),
    #fffaf2;
}

body.book-psc .hero-band::before {
  content: "";
  position: absolute;
  inset: 18% -4% auto 44%;
  height: 118px;
  opacity: 0.11;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 900 120'%3E%3Cpath d='M0 60h70l12-16 14 34 18-58 18 82 18-64 18 40 16-18h80l10-10 12 20 14-34 18 56 18-42 16 20 12-10h95l12-16 14 34 18-58 18 82 18-64 18 40 16-18h80l12-18 16 36 18-64 18 92 18-70 18 44 14-20h72' fill='none' stroke='%23c74235' stroke-width='5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / cover no-repeat;
  pointer-events: none;
}

body.book-psc .hero-grid,
body.book-psc .book-preview {
  position: relative;
  z-index: 1;
}

body.book-psc .hero-grid p {
  color: #6e625a;
}

body.book-psc .hero-grid h1,
body.book-xfgcs .hero-grid h1 {
  text-wrap: balance;
}

body.book-psc .hero-grid h1 {
  word-break: keep-all;
}

body.book-psc .hero-band .secondary-button,
body.book-psc .hero-band .ghost-button {
  color: var(--brand-strong);
  border-color: rgba(147, 44, 36, 0.32);
  background: rgba(255, 255, 255, 0.72);
}

body.book-psc .book-preview {
  gap: 10px;
  padding: 16px;
  border: 1px solid #ead7c8;
  border-radius: 28px;
  background: rgba(255, 255, 255, 0.68);
  box-shadow: 0 22px 50px rgba(101, 64, 43, 0.16);
  backdrop-filter: blur(8px);
}

body.book-psc .book-preview img {
  border: 5px solid #fff;
  border-radius: 15px;
  box-shadow: 0 10px 24px rgba(70, 43, 31, 0.16);
}

body.book-psc .book-preview img:nth-child(1),
body.book-psc .book-preview img:nth-child(4) {
  transform: translateY(-4px) rotate(-1deg);
}

body.book-psc .book-preview img:nth-child(2),
body.book-psc .book-preview img:nth-child(3) {
  transform: translateY(4px) rotate(1deg);
}

body.book-psc .panel,
body.book-psc .stat,
body.book-psc .course-item,
body.book-psc .practice-item,
body.book-psc .paper-card,
body.book-psc .question,
body.book-psc .review-card,
body.book-psc .history-row,
body.book-psc .empty-state {
  border-color: #e5d8ca;
}

body.book-psc .course-item.active,
body.book-psc .practice-item.active,
body.book-psc .paper-card.active {
  border-color: var(--brand);
  background: linear-gradient(110deg, var(--brand-soft), #fffdf8 64%, var(--accent-soft));
  box-shadow: 0 10px 28px rgba(146, 57, 43, 0.12);
}

body.book-xfgcs .topbar {
  border-top: 4px solid var(--brand);
  border-bottom: 1px solid rgba(21, 88, 120, 0.26);
  background: rgba(246, 250, 251, 0.96);
}

body.book-xfgcs .brand-mark {
  border: 1px solid rgba(255, 255, 255, 0.36);
  border-radius: 2px;
  background: linear-gradient(145deg, #102f45, #176684);
  box-shadow: 5px 5px 0 rgba(228, 84, 50, 0.18);
}

body.book-xfgcs .nav a {
  border-radius: 2px;
}

body.book-xfgcs .nav a.active,
body.book-xfgcs .nav a:hover {
  color: #fff;
  background: #174f69;
  box-shadow: inset 4px 0 0 var(--brand);
}

body.book-xfgcs .hero-band {
  color: #fff;
  border-bottom: 6px solid var(--brand);
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.075) 1px, transparent 1px),
    linear-gradient(180deg, rgba(255, 255, 255, 0.075) 1px, transparent 1px),
    radial-gradient(circle at 79% 45%, rgba(228, 84, 50, 0.26), transparent 18rem),
    linear-gradient(125deg, #0b2638 0%, #104660 57%, #133042 100%);
  background-size: 32px 32px, 32px 32px, auto, auto;
}

body.book-xfgcs .hero-band::before {
  content: "";
  position: absolute;
  right: 5vw;
  top: 50%;
  width: 430px;
  aspect-ratio: 1;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 50%;
  transform: translateY(-50%);
  box-shadow: inset 0 0 0 38px rgba(255, 255, 255, 0.025), inset 0 0 0 39px rgba(255, 255, 255, 0.1), inset 0 0 0 96px rgba(255, 255, 255, 0.02);
  pointer-events: none;
}

body.book-xfgcs .hero-grid,
body.book-xfgcs .book-preview {
  position: relative;
  z-index: 1;
}

body.book-xfgcs .book-preview {
  padding: 12px;
  border: 1px solid rgba(255, 255, 255, 0.32);
  border-left: 6px solid var(--brand);
  background: rgba(5, 28, 42, 0.62);
  box-shadow: 14px 14px 0 rgba(5, 25, 37, 0.35);
}

body.book-xfgcs .book-preview img {
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 1px;
  box-shadow: 0 10px 26px rgba(0, 0, 0, 0.34);
}

body.book-xfgcs .panel,
body.book-xfgcs .stat,
body.book-xfgcs .course-item,
body.book-xfgcs .practice-item,
body.book-xfgcs .paper-card,
body.book-xfgcs .question,
body.book-xfgcs .review-card,
body.book-xfgcs .history-row,
body.book-xfgcs .empty-state {
  border-color: #c6d5dd;
  border-radius: 3px;
}

body.book-xfgcs .stat {
  border-top: 4px solid var(--blue);
}

body.book-xfgcs .course-item.active,
body.book-xfgcs .practice-item.active,
body.book-xfgcs .paper-card.active {
  border-color: var(--brand);
  border-left-width: 7px;
  background: linear-gradient(100deg, var(--brand-soft), #fbfdfe 58%, var(--blue-soft));
}

.panel {
  border: 1px solid var(--line);
  background: var(--paper);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.panel-pad {
  padding: 22px;
}

.grid {
  display: grid;
  gap: 16px;
}

.stats-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.two-grid {
  grid-template-columns: minmax(0, 0.82fr) minmax(320px, 0.38fr);
  align-items: start;
}

.quiz-layout {
  grid-template-columns: minmax(220px, 0.32fr) minmax(0, 0.95fr);
}

.quiz-layout > aside,
.quiz-layout > .paper-grid {
  min-width: 0;
}

.quiz-layout > .paper-grid {
  grid-template-columns: 1fr;
}

@media (min-width: 921px) {
  .quiz-layout > aside,
  .quiz-layout > .paper-grid {
    position: sticky;
    top: 88px;
  }
}

.lesson-grid {
  grid-template-columns: 290px minmax(0, 1fr);
  align-items: start;
}

.paper-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.focus-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 0.44fr);
  gap: 16px;
}

.focus-card {
  position: relative;
  min-height: 190px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 0 12px 28px rgba(23, 32, 51, 0.08);
  overflow: hidden;
}

.focus-card::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 5px;
  background: var(--brand);
}

.focus-card.primary-focus {
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0.72)),
    linear-gradient(90deg, var(--brand-soft), transparent);
}

.focus-card h2 {
  margin-bottom: 10px;
  line-height: 1.22;
}

.mini-metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.mini-metrics span {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  background: #fff;
  font-size: 13px;
  font-weight: 720;
}

.stat,
.course-item,
.practice-item,
.paper-card,
.user-row,
.answer-card {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 8px;
}

.stat {
  min-height: 118px;
  padding: 18px;
}

.stat strong {
  display: block;
  margin-top: 8px;
  font-size: 30px;
  line-height: 1;
}

.stat span,
.muted {
  color: var(--muted);
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--brand-strong);
  font-size: 12px;
  font-weight: 850;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero-band .eyebrow {
  color: rgba(255, 255, 255, 0.74);
}

h1,
h2,
h3 {
  letter-spacing: 0;
}

h2 {
  margin: 0 0 14px;
  font-size: 28px;
}

h3 {
  margin: 0 0 8px;
  font-size: 19px;
}

.course-list,
.practice-list,
.admin-list {
  display: grid;
  gap: 10px;
}

.course-item,
.practice-item,
.user-row {
  padding: 14px;
}

.course-item {
  text-align: left;
}

.course-item.active {
  border-color: var(--brand);
  background: var(--brand-soft);
}

.course-meta,
.card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin-top: 9px;
}

.tag {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 0 9px;
  border-radius: 999px;
  background: var(--blue-soft);
  color: var(--blue);
  font-size: 12px;
  font-weight: 780;
  white-space: nowrap;
}

.tag.good {
  color: var(--good);
  background: var(--good-soft);
}

.tag.warn {
  color: var(--accent);
  background: var(--accent-soft);
}

.tag.bad {
  color: var(--bad);
  background: var(--bad-soft);
}

.sync-indicator {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 28px;
  padding: 0 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.76);
  font-size: 12px;
  font-weight: 720;
  white-space: nowrap;
}

.sync-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--muted);
  box-shadow: 0 0 0 3px rgba(102, 112, 133, 0.12);
}

.sync-indicator[data-sync-state="synced"] {
  color: var(--good);
  border-color: rgba(4, 120, 87, 0.2);
  background: var(--good-soft);
}

.sync-indicator[data-sync-state="synced"] .sync-dot {
  background: var(--good);
  box-shadow: 0 0 0 3px rgba(4, 120, 87, 0.13);
}

.sync-indicator[data-sync-state="saving"],
.sync-indicator[data-sync-state="checking"] {
  color: var(--accent);
  border-color: rgba(180, 83, 9, 0.2);
  background: var(--accent-soft);
}

.sync-indicator[data-sync-state="saving"] .sync-dot,
.sync-indicator[data-sync-state="checking"] .sync-dot {
  background: var(--accent);
  box-shadow: 0 0 0 3px rgba(180, 83, 9, 0.13);
  animation: sync-pulse 1.2s ease-in-out infinite;
}

.sync-indicator[data-sync-state="local"] {
  color: var(--muted);
}

@keyframes sync-pulse {
  50% {
    opacity: 0.35;
  }
}

.primary-button,
.secondary-button,
.ghost-button,
.icon-button,
.segment {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  border-radius: 8px;
  border: 1px solid transparent;
  padding: 0 14px;
  font-weight: 760;
  white-space: nowrap;
  transition: transform 0.16s ease, background 0.16s ease, border-color 0.16s ease, box-shadow 0.16s ease;
}

.primary-button:hover,
.secondary-button:hover,
.ghost-button:hover,
.icon-button:hover,
.segment:hover {
  transform: translateY(-1px);
}

.primary-button {
  color: #fff;
  background: var(--brand);
}

.primary-button:hover {
  background: var(--brand-strong);
}

.secondary-button {
  color: var(--brand-strong);
  background: #fff;
  border-color: var(--line);
}

.secondary-button:hover {
  border-color: rgba(15, 118, 110, 0.34);
  box-shadow: 0 8px 18px rgba(23, 32, 51, 0.08);
}

.ghost-button {
  color: var(--ink);
  background: transparent;
  border-color: var(--line);
}

.button-small {
  min-height: 34px;
  padding: 0 11px;
  font-size: 13px;
}

.full-width {
  width: 100%;
}

.lesson-body {
  display: grid;
  gap: 16px;
}

.lesson-section {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdff;
}

.lesson-note {
  margin-top: 18px;
  padding: 14px 16px;
  border-left: 4px solid var(--accent);
  background: var(--accent-soft);
  color: var(--ink);
}

.lesson-note p {
  margin: 6px 0 0;
  color: var(--muted);
}

body.book-zhouyi {
  --ink: #2d2a26;
  --muted: #6d655b;
  --line: #ddd2c4;
  --paper: #fffdf9;
  --mist: #f6f1e9;
  --brand: #6f4e37;
  --brand-strong: #4d3527;
  --brand-soft: #efe2d2;
  --accent: #b77932;
  --accent-soft: #fbedd7;
  --blue: #336b78;
  --blue-soft: #e0eff1;
  --shadow: 0 16px 36px rgba(77, 53, 39, 0.12);
  --app-bg: #f6f1e9;
}

body.book-huangdi {
  --ink: #20383a;
  --muted: #5d7472;
  --line: #cbded9;
  --paper: #fbfdfb;
  --mist: #eef6f3;
  --brand: #2d6a63;
  --brand-strong: #1d4d48;
  --brand-soft: #dcefeb;
  --accent: #a3613b;
  --accent-soft: #f5e5d9;
  --blue: #3a7188;
  --blue-soft: #e0eef3;
  --shadow: 0 16px 36px rgba(45, 106, 99, 0.12);
  --app-bg: #eef6f3;
}

body.book-zhouyi .brand-mark,
body.book-huangdi .brand-mark {
  background: var(--brand);
  color: #fff;
}

body.book-zhouyi .hero-band,
body.book-huangdi .hero-band {
  background: var(--brand);
  border-bottom-color: var(--brand-strong);
}

body.book-zhouyi .stat,
body.book-huangdi .stat {
  background: var(--paper);
  border-color: var(--line);
}

body.book-zhouyi .course-item.active,
body.book-zhouyi .practice-item.active,
body.book-zhouyi .paper-card.active,
body.book-huangdi .course-item.active,
body.book-huangdi .practice-item.active,
body.book-huangdi .paper-card.active {
  background: var(--brand-soft);
}

.formula-list,
.tip-list,
.objective-list {
  margin: 10px 0 0;
  padding-left: 20px;
  line-height: 1.75;
}

.progress-bar {
  height: 10px;
  border-radius: 999px;
  background: #e8edf5;
  overflow: hidden;
}

.progress-bar span {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--brand), #34d399);
}

.question {
  scroll-margin-top: 104px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.quiz-panel {
  min-width: 0;
}

.quiz-toolbar {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  min-width: 0;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.quiz-toolbar h2 {
  margin-bottom: 0;
  line-height: 1.2;
}

.quiz-toolbar-meta {
  display: grid;
  gap: 8px;
  width: min(250px, 40%);
  flex: 0 0 auto;
}

.quiz-count {
  color: var(--brand-strong);
  font-size: 13px;
  font-weight: 800;
  text-align: right;
}

.quiz-meter {
  height: 8px;
  overflow: hidden;
  border-radius: 999px;
  background: #e8edf5;
}

.quiz-meter span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--brand), var(--accent));
  transition: width 0.2s ease;
}

.quiz-form {
  min-width: 0;
}

.quiz-result {
  scroll-margin-top: 104px;
}

.options {
  display: grid;
  gap: 10px;
  margin-top: 14px;
}

.option {
  cursor: pointer;
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 10px;
  align-items: start;
  min-height: 42px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  transition: border-color 0.16s ease, background 0.16s ease, box-shadow 0.16s ease, transform 0.16s ease;
}

.option:hover {
  border-color: var(--brand);
  background: var(--brand-soft);
  transform: translateY(-1px);
}

.option:focus-within {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.12);
}

.option:has(input:checked) {
  border-color: var(--brand);
  background: var(--brand-soft);
  box-shadow: inset 4px 0 0 var(--brand);
}

.option input {
  margin-top: 3px;
}

.answer-card {
  padding: 14px;
}

.answer-card.correct {
  border-color: rgba(4, 120, 87, 0.35);
  background: var(--good-soft);
}

.answer-card.wrong {
  border-color: rgba(190, 18, 60, 0.35);
  background: var(--bad-soft);
}

.question-source {
  margin-top: 8px;
  color: var(--muted);
  font-size: 12px;
}

.review-list,
.history-list {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.review-card,
.history-row,
.empty-state {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 14px;
}

.review-card h3 {
  margin: 10px 0;
  font-size: 16px;
  line-height: 1.55;
}

.review-card p {
  margin: 7px 0;
}

.review-card-head,
.history-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.history-row strong {
  display: block;
  margin-bottom: 4px;
}

.empty-state {
  background: #f8fafc;
}

.modal {
  width: min(520px, calc(100vw - 28px));
  border: 0;
  border-radius: 8px;
  padding: 0;
  box-shadow: var(--shadow);
}

.modal::backdrop {
  background: rgba(15, 23, 42, 0.42);
}

.modal-panel {
  position: relative;
  padding: 24px;
  background: #fff;
}

.modal-close {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 34px;
  padding: 0;
  background: #fff;
  border-color: var(--line);
}

.modal-head h2 {
  margin: 0 0 8px;
}

.segmented {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 6px;
  margin: 18px 0;
  padding: 5px;
  border-radius: 8px;
  background: #eef2f7;
}

.segment {
  background: transparent;
  color: var(--muted);
}

.segment.active {
  background: #fff;
  color: var(--brand-strong);
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.08);
}

.form-grid {
  display: grid;
  gap: 12px;
}

.field {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 720;
}

.field input,
.field select {
  width: 100%;
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 12px;
  color: var(--ink);
  background: #fff;
}

.hidden {
  display: none !important;
}

[hidden] {
  display: none !important;
}

.form-error {
  min-height: 20px;
  margin: 12px 0;
  color: var(--bad);
  font-weight: 720;
}

.status-page {
  max-width: 760px;
  margin: 58px auto;
  text-align: center;
}

.toast-region {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 50;
  display: grid;
  gap: 10px;
}

.toast {
  max-width: 360px;
  padding: 12px 14px;
  border-radius: 8px;
  color: #fff;
  background: #172033;
  box-shadow: var(--shadow);
  transition: 0.18s ease;
}

.footer {
  width: var(--content);
  margin: 0 auto;
  padding: 20px 0 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  justify-content: space-between;
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 920px) {
  .topbar {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .brand,
  .top-actions {
    min-width: 0;
  }

  .top-actions {
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .nav {
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 3px;
    scrollbar-width: none;
    scroll-snap-type: x proximity;
    -webkit-overflow-scrolling: touch;
  }

  .nav a {
    scroll-snap-align: center;
  }

  .nav::-webkit-scrollbar {
    display: none;
  }

  .hero-grid,
  .two-grid,
  .lesson-grid,
  .paper-grid,
  .focus-grid {
    grid-template-columns: 1fr;
  }

  .hero-grid > * {
    min-width: 0;
  }

  .stats-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .course-list,
  .practice-list,
  .quiz-layout > .paper-grid {
    display: flex;
    gap: 10px;
    overflow-x: auto;
    padding: 2px 0 8px;
    scroll-snap-type: x proximity;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }

  .course-list::-webkit-scrollbar,
  .practice-list::-webkit-scrollbar,
  .quiz-layout > .paper-grid::-webkit-scrollbar {
    display: none;
  }

  .course-item,
  .practice-item,
  .quiz-layout > .paper-grid .paper-card {
    flex: 0 0 min(78vw, 300px);
    scroll-snap-align: start;
  }

  .quiz-toolbar {
    align-items: stretch;
    flex-direction: column;
    gap: 12px;
  }

  .quiz-toolbar-meta {
    width: 100%;
  }

  .quiz-count {
    text-align: left;
  }

  .hero-grid {
    padding: 34px 0;
  }

  .book-preview {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  body.book-zjsx .hero-grid {
    grid-template-columns: 1fr;
  }

  body.book-zjsx .book-preview {
    min-height: 300px;
  }
}

@media (max-width: 560px) {
  .section {
    padding: 20px 0;
  }

  .topbar {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 6px 10px;
    padding-top: 10px;
    padding-bottom: 10px;
  }

  .brand {
    grid-column: 1;
    grid-row: 1;
  }

  .brand-mark {
    width: 38px;
    height: 38px;
  }

  .brand small {
    display: none;
  }

  .brand strong {
    font-size: 16px;
  }

  .nav {
    grid-column: 1 / -1;
    grid-row: 2;
  }

  .nav a {
    min-height: 36px;
    padding: 0 11px;
    font-size: 14px;
  }

  .top-actions {
    grid-column: 2;
    grid-row: 1;
    flex-wrap: nowrap;
    justify-content: flex-end;
    gap: 6px;
  }

  .top-actions .tag,
  .top-actions .sync-indicator,
  .top-actions .button-small {
    min-height: 34px;
  }

  .hero-grid h1 {
    font-size: 32px;
    line-height: 1.12;
    overflow-wrap: anywhere;
    word-break: break-all;
  }

  .hero-grid p {
    max-width: 100%;
    overflow-wrap: anywhere;
    word-break: break-word;
  }

  .hero-actions {
    min-width: 0;
  }

  .hero-actions > * {
    min-width: 0;
    max-width: 100%;
    white-space: normal;
    text-align: center;
  }

  .hero-band .ghost-button {
    flex: 1 1 100%;
  }

  .hero-grid {
    gap: 24px;
    padding: 28px 0;
  }

  .topbar {
    padding-left: 18px;
    padding-right: 18px;
  }

  .top-actions {
    justify-content: flex-start;
  }

  .focus-card {
    min-height: 0;
    padding: 18px;
  }

  .quiz-panel {
    padding: 16px;
  }

  .quiz-toolbar {
    position: sticky;
    top: 108px;
    z-index: 8;
    margin: -16px -16px 0;
    padding: 14px 16px;
    background: rgba(255, 255, 255, 0.96);
    box-shadow: 0 8px 18px rgba(23, 32, 51, 0.08);
    backdrop-filter: blur(12px);
  }

  .question {
    padding: 14px;
    scroll-margin-top: 200px;
  }

  .quiz-result {
    scroll-margin-top: 200px;
  }

  .quiz-toolbar h2 {
    font-size: 23px;
  }

  .book-preview {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  body.book-psc .book-preview img:nth-child(n + 3),
  body.book-xfgcs .book-preview img:nth-child(n + 3) {
    display: none;
  }

  body.book-psc .book-preview,
  body.book-xfgcs .book-preview {
    padding: 10px;
  }

  .stats-grid {
    gap: 10px;
  }

  .stat {
    min-height: 90px;
    padding: 14px;
  }

  .stat strong {
    font-size: 25px;
  }

  .course-item,
  .practice-item,
  .quiz-layout > .paper-grid .paper-card {
    flex-basis: min(82vw, 288px);
  }

  body.book-zjsx .book-preview {
    min-height: 260px;
  }

  body.book-zjsx .book-preview img:first-child {
    width: 68%;
  }

  .footer {
    display: grid;
  }

  .review-card-head,
  .history-row {
    align-items: flex-start;
    flex-direction: column;
  }
}

/* Batch 15 art-direction layer: one editorial system, two subject palettes. */
body.book-bsks,
body.book-zsb {
  --stage: #121218;
  --stage-ink: #f6f1e9;
  --stage-muted: #a8a6ad;
  --stage-line: rgba(246, 241, 233, 0.18);
  --stage-secondary: #f6f1e9;
  --stage-accent: #c99851;
  --stage-acid: #a9d6d0;
  --surface: #f7f3ec;
  --surface-strong: #eee8dc;
  --surface-line: #d4cec2;
  --ink: #15161a;
  --muted: #68666a;
  --line: #d4cec2;
  --paper: #fbf9f4;
  --mist: #f0ece4;
  --brand: #202128;
  --brand-strong: #121218;
  --brand-soft: #e8e1d6;
  --accent: var(--stage-accent);
  --accent-soft: #f3e8d3;
  --shadow: 0 24px 60px rgba(18, 18, 24, 0.12);
  --radius: 0;
  background: var(--surface);
  color: var(--ink);
}

body.book-zsb {
  --stage: #0d1b23;
  --stage-ink: #f5f0e6;
  --stage-muted: #9eabb0;
  --stage-line: rgba(245, 240, 230, 0.18);
  --stage-secondary: #f5f0e6;
  --stage-accent: #ed795c;
  --stage-acid: #cadb82;
  --surface: #f3f0e8;
  --surface-strong: #e8e3d8;
  --surface-line: #c9c4ba;
  --brand-soft: #e7e0d4;
  --accent-soft: #f5dfd6;
}

body.book-bsks .topbar,
body.book-zsb .topbar {
  grid-template-columns: auto minmax(0, 1fr) auto;
  min-height: 72px;
  padding-top: 12px;
  padding-bottom: 12px;
  border: 0;
  border-bottom: 1px solid var(--stage-line);
  background: var(--stage);
  color: var(--stage-ink);
  box-shadow: 0 10px 30px rgba(18, 18, 24, 0.12);
  backdrop-filter: none;
}

body.book-bsks .brand,
body.book-zsb .brand {
  min-width: 218px;
  color: var(--stage-ink);
}

body.book-bsks .brand-mark,
body.book-zsb .brand-mark {
  width: 44px;
  height: 44px;
  border: 1px solid var(--stage-accent);
  border-radius: 0;
  background: transparent;
  color: var(--stage-ink);
  box-shadow: 5px 5px 0 var(--stage-accent);
  font-family: Consolas, "Courier New", monospace;
  letter-spacing: 0;
}

body.book-bsks .brand small,
body.book-zsb .brand small {
  color: var(--stage-muted);
}

body.book-bsks .nav,
body.book-zsb .nav {
  justify-content: flex-end;
  gap: 2px;
  overflow-x: auto;
  scrollbar-width: none;
}

body.book-bsks .nav::-webkit-scrollbar,
body.book-zsb .nav::-webkit-scrollbar {
  display: none;
}

body.book-bsks .nav a,
body.book-zsb .nav a {
  position: relative;
  min-height: 44px;
  padding: 0 11px;
  border-radius: 0;
  color: var(--stage-muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0;
  transition: color 220ms ease, background 220ms ease;
}

body.book-bsks .nav a .lucide,
body.book-zsb .nav a .lucide {
  width: 14px;
  height: 14px;
  margin-right: 6px;
  stroke-width: 1.7;
}

body.book-bsks .nav a::after,
body.book-zsb .nav a::after {
  position: absolute;
  right: 10px;
  bottom: 6px;
  left: 10px;
  height: 2px;
  background: var(--stage-accent);
  content: "";
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 260ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

body.book-bsks .nav a:hover,
body.book-bsks .nav a.active,
body.book-zsb .nav a:hover,
body.book-zsb .nav a.active {
  color: var(--stage-ink);
  background: rgba(255, 255, 255, 0.06);
  box-shadow: none;
}

body.book-bsks .nav a:hover::after,
body.book-bsks .nav a.active::after,
body.book-zsb .nav a:hover::after,
body.book-zsb .nav a.active::after {
  transform: scaleX(1);
  transform-origin: left;
}

body.book-bsks .top-actions,
body.book-zsb .top-actions {
  min-width: 182px;
  gap: 8px;
}

body.book-bsks .top-actions .primary-button,
body.book-bsks .top-actions .secondary-button,
body.book-zsb .top-actions .primary-button,
body.book-zsb .top-actions .secondary-button {
  min-height: 40px;
  color: var(--stage-ink);
  border-color: var(--stage-line);
  background: transparent;
  box-shadow: none;
}

body.book-bsks .top-actions .primary-button:hover,
body.book-zsb .top-actions .primary-button:hover {
  color: var(--stage);
  background: var(--stage-accent);
}

body.book-bsks .top-actions .tag,
body.book-zsb .top-actions .tag,
body.book-bsks .top-actions .sync-indicator,
body.book-zsb .top-actions .sync-indicator {
  color: var(--stage-muted);
  border-color: var(--stage-line);
  background: transparent;
}

body.book-bsks .hero-band,
body.book-zsb .hero-band {
  min-height: min(780px, calc(100vh - 72px));
  isolation: isolate;
  background: var(--stage);
  color: var(--stage-ink);
  border: 0;
}

body.book-bsks .hero-band::before,
body.book-zsb .hero-band::before {
  position: absolute;
  top: 30px;
  left: max(18px, calc((100vw - 1180px) / 2));
  z-index: 0;
  color: var(--stage-accent);
  content: "FIELD / 01";
  font-family: Consolas, "Courier New", monospace;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0;
  writing-mode: vertical-rl;
  opacity: 0.9;
}

body.book-bsks .hero-band::after,
body.book-zsb .hero-band::after {
  position: absolute;
  top: 7%;
  right: -1vw;
  z-index: -1;
  color: transparent;
  content: "01";
  font-family: "Arial Narrow", Impact, sans-serif;
  font-size: clamp(220px, 34vw, 560px);
  font-weight: 900;
  line-height: 0.78;
  letter-spacing: 0;
  -webkit-text-stroke: 1px var(--stage-line);
  opacity: 0.7;
  pointer-events: none;
}

body.book-bsks .hero-grid,
body.book-zsb .hero-grid {
  position: relative;
  min-height: inherit;
  padding-top: 112px;
  padding-bottom: 86px;
  grid-template-columns: minmax(0, 0.9fr) minmax(420px, 0.8fr);
  gap: clamp(34px, 7vw, 96px);
  align-items: center;
}

body.book-bsks .hero-grid::before,
body.book-zsb .hero-grid::before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 55.4%;
  width: 1px;
  background: var(--stage-line);
  content: "";
  pointer-events: none;
}

body.book-bsks .hero-grid > div:first-child,
body.book-zsb .hero-grid > div:first-child {
  position: relative;
  z-index: 1;
  max-width: 680px;
}

body.book-bsks .hero-band .eyebrow,
body.book-zsb .hero-band .eyebrow {
  color: var(--stage-accent);
  font-family: Consolas, "Courier New", monospace;
  font-size: 11px;
  font-weight: 700;
}

body.book-bsks .hero-grid h1,
body.book-zsb .hero-grid h1 {
  max-width: 760px;
  margin: 18px 0 24px;
  color: var(--stage-ink);
  font-family: "Arial Narrow", "Microsoft YaHei", sans-serif;
  font-size: clamp(52px, 7vw, 106px);
  font-weight: 850;
  line-height: 0.88;
  text-wrap: balance;
}

body.book-bsks .hero-grid h1::selection,
body.book-zsb .hero-grid h1::selection {
  color: var(--stage);
  background: var(--stage-accent);
}

body.book-bsks .hero-grid p,
body.book-zsb .hero-grid p {
  max-width: 560px;
  color: var(--stage-muted);
  font-size: 16px;
  line-height: 1.8;
}

body.book-bsks .hero-actions,
body.book-zsb .hero-actions {
  gap: 8px;
}

body.book-bsks .hero-band .primary-button,
body.book-zsb .hero-band .primary-button {
  color: var(--stage);
  border-color: var(--stage-accent);
  background: var(--stage-accent);
  box-shadow: 6px 6px 0 var(--stage-acid);
}

body.book-bsks .hero-band .primary-button:hover,
body.book-zsb .hero-band .primary-button:hover {
  color: var(--stage);
  background: var(--stage-ink);
  box-shadow: 2px 2px 0 var(--stage-acid);
}

body.book-bsks .hero-band .secondary-button,
body.book-bsks .hero-band .ghost-button,
body.book-zsb .hero-band .secondary-button,
body.book-zsb .hero-band .ghost-button {
  color: var(--stage-ink);
  border-color: var(--stage-line);
  background: transparent;
  box-shadow: none;
}

body.book-bsks .hero-band .secondary-button:hover,
body.book-bsks .hero-band .ghost-button:hover,
body.book-zsb .hero-band .secondary-button:hover,
body.book-zsb .hero-band .ghost-button:hover {
  color: var(--stage);
  border-color: var(--stage-ink);
  background: var(--stage-ink);
}

body.book-bsks .book-preview,
body.book-zsb .book-preview {
  position: relative;
  min-height: 560px;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  transform: perspective(1200px) rotateX(var(--tilt-y, 0deg)) rotateY(var(--tilt-x, 0deg));
  transform-style: preserve-3d;
  transition: transform 480ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

body.book-bsks .book-preview::before,
body.book-zsb .book-preview::before {
  position: absolute;
  inset: 7% 3% 6% 8%;
  border: 1px solid var(--stage-line);
  content: "";
  transform: translateZ(-20px) rotate(3deg);
}

body.book-bsks .book-preview::after,
body.book-zsb .book-preview::after {
  position: absolute;
  right: 3%;
  bottom: 2%;
  color: var(--stage-accent);
  content: "ARCHIVE / PREVIEW";
  font-family: Consolas, "Courier New", monospace;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0;
  writing-mode: vertical-rl;
}

body.book-bsks .book-preview img,
body.book-zsb .book-preview img {
  position: absolute;
  width: 39%;
  height: auto;
  aspect-ratio: 3 / 4;
  border: 1px solid rgba(246, 241, 233, 0.45);
  border-radius: 0;
  box-shadow: 16px 22px 36px rgba(0, 0, 0, 0.3);
  filter: saturate(0.9) contrast(1.02);
  object-fit: cover;
  transition: transform 520ms cubic-bezier(0.16, 1, 0.3, 1), filter 320ms ease;
}

body.book-bsks .book-preview img:nth-child(1),
body.book-zsb .book-preview img:nth-child(1) {
  top: 1%;
  left: 5%;
  z-index: 1;
  transform: translateZ(42px) rotate(-7deg);
}

body.book-bsks .book-preview img:nth-child(2),
body.book-zsb .book-preview img:nth-child(2) {
  top: 9%;
  right: 5%;
  z-index: 3;
  transform: translateZ(80px) rotate(5deg);
}

body.book-bsks .book-preview img:nth-child(3),
body.book-zsb .book-preview img:nth-child(3) {
  bottom: 3%;
  left: 13%;
  z-index: 2;
  transform: translateZ(54px) rotate(4deg);
}

body.book-bsks .book-preview img:nth-child(4),
body.book-zsb .book-preview img:nth-child(4) {
  right: 0;
  bottom: 0;
  z-index: 4;
  transform: translateZ(110px) rotate(-4deg);
}

body.book-bsks .book-preview:hover img:nth-child(1),
body.book-zsb .book-preview:hover img:nth-child(1) {
  transform: translate3d(-8px, 5px, 56px) rotate(-9deg);
}

body.book-bsks .book-preview:hover img:nth-child(2),
body.book-zsb .book-preview:hover img:nth-child(2) {
  transform: translate3d(8px, -6px, 98px) rotate(7deg);
}

body.book-bsks .book-preview:hover img:nth-child(3),
body.book-zsb .book-preview:hover img:nth-child(3) {
  transform: translate3d(-4px, 7px, 68px) rotate(6deg);
}

body.book-bsks .book-preview:hover img:nth-child(4),
body.book-zsb .book-preview:hover img:nth-child(4) {
  transform: translate3d(7px, -9px, 128px) rotate(-6deg);
}

body.book-bsks .section,
body.book-zsb .section {
  padding-top: 86px;
  padding-bottom: 86px;
}

body.book-bsks .section.grid,
body.book-zsb .section.grid {
  gap: 42px;
}

body.book-bsks .stats-grid,
body.book-zsb .stats-grid {
  gap: 0;
  border-top: 1px solid var(--surface-line);
  border-bottom: 1px solid var(--surface-line);
}

body.book-bsks .stat,
body.book-zsb .stat {
  min-height: 142px;
  padding: 26px 24px 22px;
  border: 0;
  border-right: 1px solid var(--surface-line);
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

body.book-bsks .stat:last-child,
body.book-zsb .stat:last-child {
  border-right: 0;
}

body.book-bsks .stat::before,
body.book-zsb .stat::before {
  display: block;
  width: 24px;
  height: 3px;
  margin-bottom: 22px;
  background: var(--stage-accent);
  content: "";
}

body.book-bsks .stat span,
body.book-zsb .stat span {
  color: var(--muted);
  font-family: Consolas, "Courier New", monospace;
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
}

body.book-bsks .stat strong,
body.book-zsb .stat strong {
  display: block;
  margin-top: 10px;
  color: var(--ink);
  font-family: "Arial Narrow", "Microsoft YaHei", sans-serif;
  font-size: clamp(30px, 3.5vw, 52px);
  font-weight: 800;
  line-height: 0.95;
}

body.book-bsks .focus-grid,
body.book-zsb .focus-grid {
  gap: 0;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  border-top: 1px solid var(--surface-line);
  border-bottom: 1px solid var(--surface-line);
}

body.book-bsks .focus-card,
body.book-zsb .focus-card {
  min-height: 260px;
  padding: 34px 34px 30px;
  border: 0;
  border-right: 1px solid var(--surface-line);
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

body.book-bsks .focus-card:last-child,
body.book-zsb .focus-card:last-child {
  border-right: 0;
}

body.book-bsks .primary-focus,
body.book-zsb .primary-focus {
  background: var(--surface-strong);
}

body.book-bsks .focus-card h2,
body.book-zsb .focus-card h2 {
  max-width: 720px;
  font-size: clamp(28px, 4vw, 58px);
  line-height: 0.98;
}

body.book-bsks .focus-card:nth-child(2) h2,
body.book-zsb .focus-card:nth-child(2) h2 {
  font-size: clamp(32px, 5vw, 64px);
}

body.book-bsks .panel,
body.book-zsb .panel {
  border: 1px solid var(--surface-line);
  border-radius: 0;
  background: var(--paper);
  box-shadow: none;
}

body.book-bsks .panel-pad,
body.book-zsb .panel-pad {
  padding: 30px;
}

body.book-bsks .course-list,
body.book-zsb .course-list,
body.book-bsks .practice-list,
body.book-zsb .practice-list {
  gap: 0;
  align-self: start;
  border-top: 1px solid var(--surface-line);
}

body.book-bsks .course-item,
body.book-zsb .course-item,
body.book-bsks .practice-item,
body.book-zsb .practice-item {
  position: relative;
  min-height: 112px;
  padding: 20px 22px;
  border: 0;
  border-bottom: 1px solid var(--surface-line);
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  text-align: left;
  transform: none;
}

body.book-bsks .course-item::before,
body.book-zsb .course-item::before,
body.book-bsks .practice-item::before,
body.book-zsb .practice-item::before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 3px;
  background: var(--stage-accent);
  content: "";
  transform: scaleY(0);
  transform-origin: bottom;
  transition: transform 240ms ease;
}

body.book-bsks .course-item:hover,
body.book-zsb .course-item:hover,
body.book-bsks .practice-item:hover,
body.book-zsb .practice-item:hover,
body.book-bsks .course-item.active,
body.book-zsb .course-item.active,
body.book-bsks .practice-item.active,
body.book-zsb .practice-item.active {
  border-color: var(--surface-line);
  background: var(--surface-strong);
  transform: none;
}

body.book-bsks .course-item:hover::before,
body.book-zsb .course-item:hover::before,
body.book-bsks .practice-item:hover::before,
body.book-zsb .practice-item:hover::before,
body.book-bsks .course-item.active::before,
body.book-zsb .course-item.active::before,
body.book-bsks .practice-item.active::before,
body.book-zsb .practice-item.active::before {
  transform: scaleY(1);
}

body.book-bsks .course-item h3,
body.book-zsb .course-item h3,
body.book-bsks .practice-item h3,
body.book-zsb .practice-item h3 {
  font-size: 18px;
  line-height: 1.2;
}

body.book-bsks .lesson-body,
body.book-zsb .lesson-body,
body.book-bsks .quiz-panel,
body.book-zsb .quiz-panel {
  min-width: 0;
}

body.book-bsks .lesson-section,
body.book-zsb .lesson-section,
body.book-bsks .lesson-note,
body.book-zsb .lesson-note,
body.book-bsks .question,
body.book-zsb .question,
body.book-bsks .answer-card,
body.book-zsb .answer-card,
body.book-bsks .review-card,
body.book-zsb .review-card,
body.book-bsks .history-row,
body.book-zsb .history-row,
body.book-bsks .empty-state,
body.book-zsb .empty-state {
  border-radius: 0;
  box-shadow: none;
}

body.book-bsks .question,
body.book-zsb .question {
  border-color: var(--surface-line);
  background: transparent;
}

body.book-bsks .option,
body.book-zsb .option {
  border-radius: 0;
  border-color: var(--surface-line);
  background: var(--paper);
}

body.book-bsks .option:hover,
body.book-zsb .option:hover {
  border-color: var(--stage-accent);
  background: var(--surface-strong);
  transform: translateX(5px);
}

body.book-bsks .progress-bar,
body.book-zsb .progress-bar,
body.book-bsks .quiz-meter,
body.book-zsb .quiz-meter {
  height: 5px;
  border-radius: 0;
  background: var(--surface-strong);
}

body.book-bsks .progress-bar span,
body.book-zsb .progress-bar span,
body.book-bsks .quiz-meter span,
body.book-zsb .quiz-meter span {
  border-radius: 0;
  background: var(--stage-accent);
}

body.book-bsks .primary-button,
body.book-zsb .primary-button,
body.book-bsks .secondary-button,
body.book-zsb .secondary-button,
body.book-bsks .ghost-button,
body.book-zsb .ghost-button,
body.book-bsks .icon-button,
body.book-zsb .icon-button,
body.book-bsks .segment,
body.book-zsb .segment {
  min-height: 44px;
  border-radius: 0;
  letter-spacing: 0;
  transition: color 220ms ease, background 220ms ease, border-color 220ms ease, box-shadow 220ms ease, transform 220ms ease;
}

body.book-bsks .primary-button,
body.book-zsb .primary-button {
  color: var(--stage);
  border-color: var(--stage-accent);
  background: var(--stage-accent);
  box-shadow: 5px 5px 0 var(--stage-acid);
}

body.book-bsks .primary-button:hover,
body.book-zsb .primary-button:hover {
  color: var(--stage);
  background: var(--stage-ink);
  box-shadow: 1px 1px 0 var(--stage-acid);
  transform: translate(4px, 4px);
}

body.book-bsks .secondary-button,
body.book-zsb .secondary-button,
body.book-bsks .ghost-button,
body.book-zsb .ghost-button {
  color: var(--ink);
  border-color: var(--surface-line);
  background: transparent;
  box-shadow: none;
}

body.book-bsks .secondary-button:hover,
body.book-zsb .secondary-button:hover,
body.book-bsks .ghost-button:hover,
body.book-zsb .ghost-button:hover {
  color: var(--stage);
  border-color: var(--stage);
  background: var(--surface-strong);
}

body.book-bsks button > .lucide,
body.book-zsb button > .lucide,
body.book-bsks a > .lucide,
body.book-zsb a > .lucide {
  width: 15px;
  height: 15px;
  margin-right: 8px;
  stroke-width: 1.8;
}

body.book-bsks .icon-button > .lucide,
body.book-zsb .icon-button > .lucide {
  margin-right: 0;
}

body.book-bsks .modal,
body.book-zsb .modal {
  border: 1px solid var(--surface-line);
  border-radius: 0;
  background: rgba(13, 13, 18, 0.62);
}

body.book-bsks .modal::backdrop,
body.book-zsb .modal::backdrop {
  background: rgba(13, 13, 18, 0.78);
  backdrop-filter: blur(12px);
}

body.book-bsks .modal-panel,
body.book-zsb .modal-panel {
  border-top: 5px solid var(--stage-accent);
  border-radius: 0;
  background: var(--surface);
}

body.book-bsks .footer,
body.book-zsb .footer {
  border-top: 1px solid var(--surface-line);
  background: var(--surface);
}

body.book-bsks .motion-ready,
body.book-zsb .motion-ready {
  opacity: 0;
  transform: translateY(20px);
}

body.book-bsks .motion-ready.motion-in,
body.book-zsb .motion-ready.motion-in {
  animation: editorial-rise 720ms cubic-bezier(0.16, 1, 0.3, 1) forwards;
  animation-delay: calc(var(--motion-index, 0) * 38ms);
}

body.book-bsks .hero-band.motion-ready,
body.book-zsb .hero-band.motion-ready {
  transform: none;
}

body.book-bsks .hero-band.motion-ready.motion-in,
body.book-zsb .hero-band.motion-ready.motion-in {
  animation-name: stage-reveal;
  animation-duration: 860ms;
}

@keyframes editorial-rise {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes stage-reveal {
  from { opacity: 0; clip-path: inset(0 0 12% 0); }
  to { opacity: 1; clip-path: inset(0 0 0 0); }
}

@media (max-width: 920px) {
  body.book-bsks .topbar,
  body.book-zsb .topbar {
    grid-template-columns: 1fr auto;
  }

  body.book-bsks .nav,
  body.book-zsb .nav {
    grid-column: 1 / -1;
    justify-content: flex-start;
  }

  body.book-bsks .hero-grid,
  body.book-zsb .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
    padding-top: 86px;
    padding-bottom: 64px;
  }

  body.book-bsks .hero-grid::before,
  body.book-zsb .hero-grid::before {
    left: 14%;
    opacity: 0.4;
  }

  body.book-bsks .book-preview,
  body.book-zsb .book-preview {
    width: min(560px, 100%);
    min-height: 500px;
    margin-left: auto;
  }

  body.book-bsks .focus-grid,
  body.book-zsb .focus-grid {
    grid-template-columns: 1fr;
  }

  body.book-bsks .focus-card,
  body.book-zsb .focus-card {
    border-right: 0;
    border-bottom: 1px solid var(--surface-line);
  }

  body.book-bsks .focus-card:last-child,
  body.book-zsb .focus-card:last-child {
    border-bottom: 0;
  }
}

@media (max-width: 560px) {
  body.book-bsks .topbar,
  body.book-zsb .topbar {
    min-height: 0;
    padding: 12px 16px 8px;
  }

  body.book-bsks .brand,
  body.book-zsb .brand {
    min-width: 0;
  }

  body.book-bsks .brand small,
  body.book-zsb .brand small {
    display: none;
  }

  body.book-bsks .nav,
  body.book-zsb .nav {
    margin: 4px -16px 0;
    padding: 0 16px 4px;
  }

  body.book-bsks .nav a,
  body.book-zsb .nav a {
    flex: 0 0 auto;
    padding: 0 9px;
    font-size: 11px;
  }

  body.book-bsks .top-actions,
  body.book-zsb .top-actions {
    min-width: 0;
  }

  body.book-bsks .top-actions .tag,
  body.book-zsb .top-actions .tag,
  body.book-bsks .top-actions .sync-indicator,
  body.book-zsb .top-actions .sync-indicator {
    display: none;
  }

  body.book-bsks .hero-grid,
  body.book-zsb .hero-grid {
    width: min(calc(100% - 32px), 1180px);
    padding-top: 78px;
    padding-bottom: 40px;
  }

  body.book-bsks .hero-grid h1,
  body.book-zsb .hero-grid h1 {
    max-width: 100%;
    font-size: clamp(46px, 13vw, 68px);
  }

  body.book-bsks .hero-grid p,
  body.book-zsb .hero-grid p {
    font-size: 15px;
    line-height: 1.7;
  }

  body.book-bsks .hero-actions > *,
  body.book-zsb .hero-actions > * {
    flex: 1 1 100%;
  }

  body.book-bsks .book-preview,
  body.book-zsb .book-preview {
    min-height: 380px;
  }

  body.book-bsks .book-preview::after,
  body.book-zsb .book-preview::after {
    right: 0;
  }

  body.book-bsks .stat,
  body.book-zsb .stat {
    min-height: 118px;
    padding: 20px 16px;
  }

  body.book-bsks .stat strong,
  body.book-zsb .stat strong {
    font-size: 30px;
  }

  body.book-bsks .focus-card,
  body.book-zsb .focus-card,
  body.book-bsks .panel-pad,
  body.book-zsb .panel-pad {
    padding: 22px 18px;
  }

  body.book-bsks .lesson-grid,
  body.book-zsb .lesson-grid,
  body.book-bsks .quiz-layout,
  body.book-zsb .quiz-layout,
  body.book-bsks .two-grid,
  body.book-zsb .two-grid {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  body.book-bsks .motion-ready,
  body.book-zsb .motion-ready,
  body.book-bsks .motion-ready.motion-in,
  body.book-zsb .motion-ready.motion-in {
    opacity: 1;
    transform: none;
    animation: none;
  }

  body.book-bsks .book-preview,
  body.book-zsb .book-preview,
  body.book-bsks .book-preview img,
  body.book-zsb .book-preview img {
    transition: none;
  }
}

/* Batch 13 themes: keep the two subjects visually distinct while sharing the study UI. */
body.book-zcyh {
  --ink: #10233f;
  --muted: #52647e;
  --line: #d7dfeb;
  --paper: #f4f7fb;
  --surface: #ffffff;
  --accent: #b57b19;
  --accent-strong: #8a5a0a;
  --accent-soft: #f8edcf;
  background: #edf2f8;
  color: var(--ink);
}

body.book-zcyh .topbar {
  background: #10233f;
  border-bottom-color: #223b5e;
}

body.book-zcyh .brand-mark {
  background: #c69637;
  color: #10233f;
}

body.book-zcyh .brand strong,
body.book-zcyh .brand small,
body.book-zcyh .nav a {
  color: #f5e7c3;
}

body.book-zcyh .nav a.active,
body.book-zcyh .nav a:hover {
  background: #c69637;
  color: #10233f;
}

body.book-zcyh .hero-band {
  background: #10233f;
  border-bottom: 1px solid #c69637;
}

body.book-zcyh .hero-band .eyebrow,
body.book-zcyh .hero-band h1,
body.book-zcyh .hero-band p {
  color: #f6e9ca;
}

body.book-zcyh .hero-band .secondary-button,
body.book-zcyh .hero-band .ghost-button {
  border-color: #d3a64c;
  color: #f6e9ca;
}

body.book-zcyh .book-preview {
  background: #d8b15b;
  border-color: #d8b15b;
}

body.book-zcyh .book-preview img {
  border-color: #fff0c7;
}

body.book-zcyh .panel,
body.book-zcyh .stat,
body.book-zcyh .course-item,
body.book-zcyh .practice-item,
body.book-zcyh .paper-card,
body.book-zcyh .question,
body.book-zcyh .review-card,
body.book-zcyh .history-row,
body.book-zcyh .empty-state {
  border-color: var(--line);
  background: var(--surface);
}

body.book-zcyh .stat strong,
body.book-zcyh .course-item h3,
body.book-zcyh .practice-item h3,
body.book-zcyh .paper-card h3 {
  color: var(--accent-strong);
}

body.book-zcyh .course-item.active,
body.book-zcyh .practice-item.active,
body.book-zcyh .paper-card.active {
  border-color: #c69637;
  background: var(--accent-soft);
}

body.book-ielts {
  --ink: #15243b;
  --muted: #5e6d80;
  --line: #d9dfe7;
  --paper: #faf9f5;
  --surface: #ffffff;
  --accent: #b4862d;
  --accent-strong: #1f4370;
  --accent-soft: #f6f0df;
  background: #f4f3ef;
  color: var(--ink);
}

body.book-ielts .topbar {
  background: #fdfcf8;
  border-bottom-color: #d8c58e;
}

body.book-ielts .brand-mark {
  background: #1f4370;
  color: #f7edce;
}

body.book-ielts .brand strong,
body.book-ielts .brand small,
body.book-ielts .nav a {
  color: #1f4370;
}

body.book-ielts .nav a.active,
body.book-ielts .nav a:hover {
  background: #1f4370;
  color: #ffffff;
}

body.book-ielts .hero-band {
  background: #1f4370;
  border-bottom: 1px solid #b4862d;
}

body.book-ielts .hero-band .eyebrow,
body.book-ielts .hero-band h1,
body.book-ielts .hero-band p {
  color: #f8f2df;
}

body.book-ielts .hero-band .secondary-button,
body.book-ielts .hero-band .ghost-button {
  border-color: #dbc37c;
  color: #fff6df;
}

body.book-ielts .book-preview {
  background: #e5d9b9;
  border-color: #d4bb70;
}

body.book-ielts .book-preview img {
  border-color: #fffdf7;
}

body.book-ielts .panel,
body.book-ielts .stat,
body.book-ielts .course-item,
body.book-ielts .practice-item,
body.book-ielts .paper-card,
body.book-ielts .question,
body.book-ielts .review-card,
body.book-ielts .history-row,
body.book-ielts .empty-state {
  border-color: var(--line);
  background: var(--surface);
}

body.book-ielts .stat strong,
body.book-ielts .course-item h3,
body.book-ielts .practice-item h3,
body.book-ielts .paper-card h3 {
  color: var(--accent-strong);
}

body.book-ielts .course-item.active,
body.book-ielts .practice-item.active,
body.book-ielts .paper-card.active {
  border-color: #b4862d;
  background: var(--accent-soft);
}

body.book-cetset {
  --ink: #1b2840;
  --muted: #647187;
  --line: #d5dce7;
  --paper: #fbfcff;
  --surface: #ffffff;
  --accent: #dc6c3f;
  --accent-strong: #1f527d;
  --accent-soft: #fff0e8;
  background: #f1f5fa;
  color: var(--ink);
}

body.book-cetset .topbar {
  background: #ffffff;
  border-top: 4px solid #dc6c3f;
  border-bottom-color: #cbd8e8;
}

body.book-cetset .brand-mark {
  background: #1f527d;
  color: #fff4e9;
}

body.book-cetset .brand strong,
body.book-cetset .brand small,
body.book-cetset .nav a {
  color: #1f527d;
}

body.book-cetset .nav a.active,
body.book-cetset .nav a:hover {
  background: #e7f0f8;
  color: #173e60;
  box-shadow: inset 0 -3px 0 #dc6c3f;
}

body.book-cetset .hero-band {
  background: #1f527d;
  border-bottom: 1px solid #dc6c3f;
}

body.book-cetset .hero-band .eyebrow,
body.book-cetset .hero-band h1,
body.book-cetset .hero-band p {
  color: #f7fbff;
}

body.book-cetset .hero-band .secondary-button,
body.book-cetset .hero-band .ghost-button {
  border-color: #f0b28f;
  color: #fff7ef;
}

body.book-cetset .book-preview {
  background: #f0c2a5;
  border-color: #dc6c3f;
}

body.book-cetset .book-preview img {
  border-color: #fff8f0;
}

body.book-cetset .panel,
body.book-cetset .stat,
body.book-cetset .course-item,
body.book-cetset .practice-item,
body.book-cetset .paper-card,
body.book-cetset .question,
body.book-cetset .review-card,
body.book-cetset .history-row,
body.book-cetset .empty-state {
  border-color: var(--line);
  background: var(--surface);
}

body.book-cetset .stat strong,
body.book-cetset .course-item h3,
body.book-cetset .practice-item h3,
body.book-cetset .paper-card h3 {
  color: var(--accent-strong);
}

body.book-cetset .course-item.active,
body.book-cetset .practice-item.active,
body.book-cetset .paper-card.active {
  border-color: #dc6c3f;
  background: var(--accent-soft);
}

body.book-kyfs {
  --ink: #20302f;
  --muted: #667875;
  --line: #d3dfda;
  --paper: #f8fbf9;
  --surface: #ffffff;
  --accent: #4f8d70;
  --accent-strong: #255348;
  --accent-soft: #e6f2eb;
  background: #eef5f1;
  color: var(--ink);
}

body.book-kyfs .topbar {
  background: #fbfefc;
  border-top: 4px solid #4f8d70;
  border-bottom-color: #c7d9d1;
}

body.book-kyfs .brand-mark {
  background: #255348;
  color: #eef8f2;
}

body.book-kyfs .brand strong,
body.book-kyfs .brand small,
body.book-kyfs .nav a {
  color: #255348;
}

body.book-kyfs .nav a.active,
body.book-kyfs .nav a:hover {
  background: #e1f0e8;
  color: #183f38;
  box-shadow: inset 0 -3px 0 #c58a3d;
}

body.book-kyfs .hero-band {
  background: #255348;
  border-bottom: 1px solid #c58a3d;
}

body.book-kyfs .hero-band .eyebrow,
body.book-kyfs .hero-band h1,
body.book-kyfs .hero-band p {
  color: #f1f8f3;
}

body.book-kyfs .hero-band .secondary-button,
body.book-kyfs .hero-band .ghost-button {
  border-color: #d6b27a;
  color: #fff9ef;
}

body.book-kyfs .book-preview {
  background: #cfe2d7;
  border-color: #4f8d70;
}

body.book-kyfs .book-preview img {
  border-color: #f6fff8;
}

body.book-kyfs .panel,
body.book-kyfs .stat,
body.book-kyfs .course-item,
body.book-kyfs .practice-item,
body.book-kyfs .paper-card,
body.book-kyfs .question,
body.book-kyfs .review-card,
body.book-kyfs .history-row,
body.book-kyfs .empty-state {
  border-color: var(--line);
  background: var(--surface);
}

body.book-kyfs .stat strong,
body.book-kyfs .course-item h3,
body.book-kyfs .practice-item h3,
body.book-kyfs .paper-card h3 {
  color: var(--accent-strong);
}

body.book-kyfs .course-item.active,
body.book-kyfs .practice-item.active,
body.book-kyfs .paper-card.active {
  border-color: #4f8d70;
  background: var(--accent-soft);
}

@media (max-width: 560px) {
  body.book-zcyh .book-preview,
  body.book-ielts .book-preview,
  body.book-cetset .book-preview,
  body.book-kyfs .book-preview {
    padding: 10px;
  }
}

/* Shared visual system: a dark editorial stage, paper-like study surfaces, and quiet motion. */
:root {
  --content: min(1280px, calc(100vw - 48px));
  --display-face: "Arial Black", "Microsoft YaHei", "PingFang SC", sans-serif;
  --stage: #0b1116;
  --stage-ink: #f8f4ea;
  --stage-line: rgba(248, 244, 234, 0.22);
}

body[class*="book-"] {
  --stage-accent: var(--accent, #d78454);
  --stage-secondary: var(--brand-strong, #234d6d);
  background: #edece7;
  letter-spacing: 0;
}

body[class*="book-"]::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    repeating-linear-gradient(90deg, rgba(18, 28, 35, 0.035) 0 1px, transparent 1px 48px),
    repeating-linear-gradient(0deg, rgba(18, 28, 35, 0.025) 0 1px, transparent 1px 48px);
  opacity: 0.5;
}

body[class*="book-"] .topbar {
  grid-template-columns: auto minmax(0, 1fr) auto;
  min-height: 74px;
  padding-top: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(18, 28, 35, 0.17);
  background: rgba(245, 244, 239, 0.86);
  backdrop-filter: blur(24px) saturate(130%);
}

body[class*="book-"] .brand {
  gap: 12px;
  min-width: 224px;
}

body[class*="book-"] .brand-mark {
  width: 44px;
  height: 44px;
  border: 1px solid var(--stage-secondary);
  border-radius: 2px;
  background: var(--stage-secondary);
  color: var(--stage-ink);
  box-shadow: 5px 5px 0 var(--stage-accent);
  font-family: Consolas, "Courier New", monospace;
  letter-spacing: 0;
}

body[class*="book-"] .brand strong {
  color: var(--ink);
  font-family: var(--display-face);
  font-size: 16px;
  letter-spacing: 0;
}

body[class*="book-"] .brand small {
  margin-top: 3px;
  color: var(--muted);
  max-width: 230px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

body[class*="book-"] .nav {
  justify-content: flex-end;
  gap: 2px;
}

body[class*="book-"] .nav a {
  position: relative;
  min-height: 42px;
  border-radius: 0;
  padding: 0 12px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 760;
  transition: color 0.2s ease, background 0.2s ease;
}

body[class*="book-"] .nav a::after {
  content: "";
  position: absolute;
  right: 12px;
  bottom: 4px;
  left: 12px;
  height: 2px;
  background: var(--stage-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.24s ease;
}

body[class*="book-"] .nav a:hover,
body[class*="book-"] .nav a.active {
  color: var(--ink);
  background: transparent;
  box-shadow: none;
}

body[class*="book-"] .nav a:hover::after,
body[class*="book-"] .nav a.active::after {
  transform: scaleX(1);
}

body[class*="book-"] .top-actions {
  min-width: 190px;
}

body[class*="book-"] .hero-band {
  min-height: 610px;
  isolation: isolate;
  color: var(--stage-ink);
  background-color: var(--stage);
  background-image:
    repeating-linear-gradient(90deg, transparent 0 118px, var(--stage-line) 119px 120px),
    repeating-linear-gradient(0deg, transparent 0 118px, rgba(248, 244, 234, 0.1) 119px 120px);
  border-top: 0;
  border-bottom: 1px solid var(--stage-line);
}

body[class*="book-"] .hero-band::before {
  content: "FIELD / 01";
  position: absolute;
  top: 28px;
  right: max(24px, calc((100vw - 1280px) / 2));
  z-index: -1;
  color: rgba(248, 244, 234, 0.14);
  font-family: Consolas, "Courier New", monospace;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0;
}

body[class*="book-"] .hero-band::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    linear-gradient(90deg, transparent calc(var(--pointer-x, 50%) - 1px), rgba(248, 244, 234, 0.28) var(--pointer-x, 50%), transparent calc(var(--pointer-x, 50%) + 1px)),
    linear-gradient(0deg, transparent calc(var(--pointer-y, 50%) - 1px), rgba(248, 244, 234, 0.2) var(--pointer-y, 50%), transparent calc(var(--pointer-y, 50%) + 1px));
  opacity: 0.7;
}

body[class*="book-"] .hero-grid {
  position: relative;
  z-index: 1;
  min-height: 610px;
  padding: 88px 0 74px;
  grid-template-columns: minmax(0, 1.08fr) minmax(310px, 0.62fr);
  gap: 64px;
  align-items: end;
}

body[class*="book-"] .hero-grid > div:first-child {
  animation: hero-copy-in 0.8s cubic-bezier(0.22, 1, 0.36, 1) both;
}

body[class*="book-"] .hero-grid h1 {
  max-width: 11ch;
  margin: 16px 0 24px;
  color: var(--stage-ink);
  font-family: var(--display-face);
  font-size: 72px;
  font-weight: 900;
  line-height: 0.94;
  letter-spacing: 0;
  text-wrap: balance;
}

body[class*="book-"] .hero-grid p {
  max-width: 680px;
  color: rgba(248, 244, 234, 0.74);
  font-size: 16px;
  line-height: 1.8;
}

body[class*="book-"] .hero-grid .eyebrow {
  color: var(--stage-accent);
  letter-spacing: 0;
}

body[class*="book-"] .hero-actions {
  gap: 8px;
  margin-top: 34px;
}

body[class*="book-"] .book-preview {
  position: relative;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  padding: 18px 18px 24px;
  border: 1px solid rgba(248, 244, 234, 0.32);
  border-radius: 0;
  background: rgba(248, 244, 234, 0.08);
  box-shadow: 12px 12px 0 var(--stage-accent);
  transform: rotate(2deg);
  animation: preview-in 1s 0.1s cubic-bezier(0.22, 1, 0.36, 1) both;
}

body[class*="book-"] .book-preview::before {
  content: "PREVIEW / 04";
  position: absolute;
  top: -28px;
  left: 0;
  color: rgba(248, 244, 234, 0.64);
  font-family: Consolas, "Courier New", monospace;
  font-size: 11px;
  letter-spacing: 0;
}

body[class*="book-"] .book-preview img {
  position: relative;
  z-index: 1;
  border: 1px solid rgba(248, 244, 234, 0.35);
  border-radius: 0;
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.25);
  transition: transform 0.35s cubic-bezier(0.22, 1, 0.36, 1), box-shadow 0.35s ease;
}

body[class*="book-"] .book-preview img:nth-child(1) {
  transform: translateY(18px) rotate(-3deg);
}

body[class*="book-"] .book-preview img:nth-child(2) {
  transform: translateY(-10px) rotate(2deg);
}

body[class*="book-"] .book-preview img:nth-child(3) {
  transform: translateY(14px) rotate(1deg);
}

body[class*="book-"] .book-preview img:nth-child(4) {
  transform: translateY(-16px) rotate(-2deg);
}

body[class*="book-"] .book-preview:hover img:nth-child(1) {
  transform: translate(-8px, 12px) rotate(-6deg);
}

body[class*="book-"] .book-preview:hover img:nth-child(2) {
  transform: translate(8px, -16px) rotate(5deg);
}

body[class*="book-"] .book-preview:hover img:nth-child(3) {
  transform: translate(-6px, 18px) rotate(4deg);
}

body[class*="book-"] .book-preview:hover img:nth-child(4) {
  transform: translate(6px, -20px) rotate(-5deg);
}

body[class*="book-"] .section {
  padding-top: 72px;
  padding-bottom: 72px;
}

body[class*="book-"] .section > .eyebrow,
body[class*="book-"] .panel .eyebrow {
  color: var(--stage-secondary);
  letter-spacing: 0;
}

body[class*="book-"] .panel {
  border-radius: 0;
  box-shadow: 0 16px 40px rgba(16, 26, 34, 0.08);
}

body[class*="book-"] .panel-pad {
  padding: 28px;
}

body[class*="book-"] .stats-grid {
  gap: 0;
  border-top: 1px solid rgba(18, 28, 35, 0.18);
  border-bottom: 1px solid rgba(18, 28, 35, 0.18);
}

body[class*="book-"] .stat {
  min-height: 148px;
  padding: 24px 22px;
  border: 0;
  border-right: 1px solid rgba(18, 28, 35, 0.14);
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

body[class*="book-"] .stat:last-child {
  border-right: 0;
}

body[class*="book-"] .stat strong {
  color: var(--stage-secondary);
  font-family: var(--display-face);
  font-size: 34px;
}

body[class*="book-"] .stat span {
  font-size: 12px;
  letter-spacing: 0;
  text-transform: uppercase;
}

body[class*="book-"] .focus-grid {
  gap: 22px;
  margin-top: 22px;
}

body[class*="book-"] .focus-card {
  min-height: 220px;
  padding: 30px;
  border: 1px solid rgba(18, 28, 35, 0.16);
  border-radius: 0;
  background: rgba(255, 255, 255, 0.58);
  box-shadow: none;
}

body[class*="book-"] .focus-card::before {
  width: 8px;
  background: var(--stage-accent);
}

body[class*="book-"] .focus-card.primary-focus {
  color: var(--stage-ink);
  background: var(--stage);
}

body[class*="book-"] .focus-card.primary-focus .eyebrow,
body[class*="book-"] .focus-card.primary-focus .muted {
  color: rgba(248, 244, 234, 0.66);
}

body[class*="book-"] .focus-card.primary-focus h2 {
  color: var(--stage-ink);
}

body[class*="book-"] .mini-metrics span {
  border-radius: 0;
  background: transparent;
}

body[class*="book-"] .primary-focus .mini-metrics span {
  border-color: rgba(248, 244, 234, 0.28);
  color: rgba(248, 244, 234, 0.76);
  background: transparent;
}

body[class*="book-"] .course-item,
body[class*="book-"] .practice-item,
body[class*="book-"] .paper-card,
body[class*="book-"] .question,
body[class*="book-"] .review-card,
body[class*="book-"] .history-row,
body[class*="book-"] .empty-state,
body[class*="book-"] .user-row,
body[class*="book-"] .answer-card {
  border-radius: 0;
  box-shadow: none;
}

body[class*="book-"] .course-item,
body[class*="book-"] .practice-item,
body[class*="book-"] .paper-card {
  position: relative;
  overflow: hidden;
  padding: 18px;
  transition: transform 0.22s ease, border-color 0.22s ease, background 0.22s ease;
}

body[class*="book-"] .course-item::after,
body[class*="book-"] .practice-item::after,
body[class*="book-"] .paper-card::after {
  content: "";
  position: absolute;
  top: 14px;
  right: 16px;
  width: 24px;
  height: 2px;
  color: var(--stage-accent);
  background: var(--stage-accent);
  opacity: 0;
  transform: translate(-5px, 5px);
  transition: opacity 0.2s ease, transform 0.2s ease;
}

body[class*="book-"] .course-item:hover,
body[class*="book-"] .practice-item:hover,
body[class*="book-"] .paper-card:hover {
  border-color: var(--stage-accent);
  transform: translateY(-4px);
}

body[class*="book-"] .course-item:hover::after,
body[class*="book-"] .practice-item:hover::after,
body[class*="book-"] .paper-card:hover::after,
body[class*="book-"] .course-item.active::after,
body[class*="book-"] .practice-item.active::after,
body[class*="book-"] .paper-card.active::after {
  opacity: 1;
  transform: translate(0, 0);
}

body[class*="book-"] .course-item.active,
body[class*="book-"] .practice-item.active,
body[class*="book-"] .paper-card.active {
  border-color: var(--stage-accent);
  border-left-width: 7px;
  background: var(--accent-soft, #f5ebdc);
}

body[class*="book-"] .tag,
body[class*="book-"] .sync-indicator {
  border-radius: 0;
}

body[class*="book-"] .primary-button,
body[class*="book-"] .secondary-button,
body[class*="book-"] .ghost-button,
body[class*="book-"] .icon-button,
body[class*="book-"] .segment {
  min-height: 44px;
  border-radius: 2px;
  letter-spacing: 0;
}

body[class*="book-"] .primary-button {
  color: var(--stage-ink);
  background: var(--stage-secondary);
  box-shadow: 5px 5px 0 var(--stage-accent);
}

body[class*="book-"] .primary-button:hover {
  background: var(--stage);
  box-shadow: 2px 2px 0 var(--stage-accent);
  transform: translate(3px, 3px);
}

body[class*="book-"] .secondary-button,
body[class*="book-"] .ghost-button {
  color: var(--stage-secondary);
  border-color: rgba(18, 28, 35, 0.25);
  background: transparent;
}

body[class*="book-"] .secondary-button:hover,
body[class*="book-"] .ghost-button:hover {
  color: var(--stage-secondary);
  border-color: var(--stage-accent);
  background: rgba(255, 255, 255, 0.62);
}

body[class*="book-"] .hero-band .primary-button {
  color: var(--stage);
  background: var(--stage-ink);
  box-shadow: 5px 5px 0 var(--stage-accent);
}

body[class*="book-"] .hero-band .primary-button:hover {
  color: var(--stage);
  background: var(--stage-accent);
}

body[class*="book-"] .hero-band .secondary-button,
body[class*="book-"] .hero-band .ghost-button {
  color: var(--stage-ink);
  border-color: rgba(248, 244, 234, 0.38);
  background: transparent;
}

body[class*="book-"] .hero-band .secondary-button:hover,
body[class*="book-"] .hero-band .ghost-button:hover {
  color: var(--stage-ink);
  border-color: var(--stage-accent);
  background: rgba(248, 244, 234, 0.1);
}

body[class*="book-"] button > .lucide,
body[class*="book-"] a > .lucide,
body[class*="book-"] button > [data-lucide],
body[class*="book-"] a > [data-lucide] {
  width: 16px;
  height: 16px;
  margin-right: 8px;
  flex: 0 0 auto;
  stroke-width: 1.8;
}

body[class*="book-"] .icon-button > .lucide,
body[class*="book-"] .icon-button > [data-lucide] {
  margin-right: 0;
}

body[class*="book-"] .brand-mark > .lucide,
body[class*="book-"] .brand-mark > [data-lucide] {
  width: 20px;
  height: 20px;
  margin-right: 0;
}

body[class*="book-"] .eyebrow,
body[class*="book-"] h1,
body[class*="book-"] h2,
body[class*="book-"] h3 {
  letter-spacing: 0;
}

body[class*="book-"] .quiz-panel,
body[class*="book-"] .lesson-section {
  border-radius: 0;
  box-shadow: none;
}

body[class*="book-"] .quiz-toolbar {
  padding-bottom: 22px;
  border-bottom-color: rgba(18, 28, 35, 0.16);
}

body[class*="book-"] .quiz-meter span,
body[class*="book-"] .progress-bar span {
  background: var(--stage-accent);
}

body[class*="book-"] .option {
  border-radius: 0;
  transition: border-color 0.2s ease, background 0.2s ease, transform 0.2s ease;
}

body[class*="book-"] .option:hover {
  transform: translateX(4px);
}

body[class*="book-"] .modal {
  border-radius: 0;
}

body[class*="book-"] .modal-panel {
  border-top: 8px solid var(--stage-accent);
}

body[class*="book-"] .modal-close {
  border-radius: 0;
}

body[class*="book-"] .footer {
  border-top: 1px solid rgba(18, 28, 35, 0.14);
}

@keyframes hero-copy-in {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes preview-in {
  from { opacity: 0; transform: translate(26px, 18px) rotate(8deg); }
  to { opacity: 1; transform: rotate(2deg); }
}

@media (prefers-reduced-motion: reduce) {
  body[class*="book-"] .hero-grid > div:first-child,
  body[class*="book-"] .book-preview {
    animation: none;
  }

  body[class*="book-"] *,
  body[class*="book-"] *::before,
  body[class*="book-"] *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}

@media (max-width: 920px) {
  body[class*="book-"] .topbar {
    grid-template-columns: 1fr;
  }

  body[class*="book-"] .nav {
    justify-content: flex-start;
  }

  body[class*="book-"] .hero-grid {
    min-height: auto;
    padding: 78px 0 62px;
    grid-template-columns: 1fr;
    gap: 52px;
  }

  body[class*="book-"] .book-preview {
    width: min(520px, 100%);
    margin-left: auto;
  }
}

@media (max-width: 560px) {
  :root {
    --content: min(100% - 32px, 1280px);
  }

  body[class*="book-"] {
    overflow-x: hidden;
  }

  body[class*="book-"] .topbar {
    padding-right: 16px;
    padding-left: 16px;
  }

  body[class*="book-"] .brand {
    min-width: 0;
  }

  body[class*="book-"] .top-actions {
    min-width: 0;
    gap: 4px;
  }

  body[class*="book-"] .top-actions .button-small {
    padding-right: 8px;
    padding-left: 8px;
  }

  body[class*="book-"] .top-actions .button-small > .lucide {
    margin-right: 4px;
  }

  body[class*="book-"] .hero-grid {
    padding-top: 60px;
  }

  body[class*="book-"] .hero-grid h1 {
    max-width: 100%;
    font-size: 42px;
    line-height: 1;
  }

  body[class*="book-"] .hero-grid p {
    font-size: 15px;
  }

  body[class*="book-"] .book-preview {
    padding: 14px 14px 18px;
    box-shadow: 8px 8px 0 var(--stage-accent);
  }

  body[class*="book-"] .stats-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  body[class*="book-"] .stat {
    min-height: 112px;
    padding: 18px 14px;
  }

  body[class*="book-"] .stat:nth-child(2) {
    border-right: 0;
  }

  body[class*="book-"] .stat:nth-child(-n + 2) {
    border-bottom: 1px solid rgba(18, 28, 35, 0.14);
  }

  body[class*="book-"] .stat strong {
    font-size: 26px;
  }

  body[class*="book-"] .panel-pad,
  body[class*="book-"] .focus-card {
    padding: 20px;
  }

  body[class*="book-"] .hero-actions > * {
    flex: 1 1 100%;
  }
}