:root {
  --bg-dark: #111111;
  --bg-dark-soft: #1c1c1c;
  --bg-paper: #e4ddd4;
  --bg-page: #fffdf9;
  --bg-page-soft: #f7f2eb;
  --text-strong: #241d14;
  --text-body: #4e4335;
  --text-soft: #7b6f61;
  --line: #d8d0c8;
  --line-strong: #c4b9ae;
  --accent: #b46434;
  --accent-dark: #8f4a23;
  --accent-warm: #cd6e53;
  --accent-olive: #6b8258;
  --accent-blue: #5b7693;
  --ok: #3f7d3d;
  --code-bg: #241c14;
  --code-text: #e4c99f;
  --shadow-page: 0 12px 36px rgba(0, 0, 0, 0.1);
  --radius-lg: 16px;
  --radius-md: 10px;
  --font-display: "Lora", "Noto Serif SC", "Source Han Serif SC", serif;
  --font-body: "IBM Plex Sans", "Inter", "PingFang SC", sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  color: var(--text-strong);
}

body.page-home {
  min-height: 100vh;
  background:
    radial-gradient(circle at top right, rgba(205, 110, 83, 0.18), transparent 26%),
    linear-gradient(180deg, #0f0f10 0%, #141313 100%);
  color: #efe7de;
  padding: 56px 28px 84px;
}

a {
  color: inherit;
}

.home-shell {
  max-width: 980px;
  margin: 0 auto;
}

.site-brand {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 68px;
}

.site-brand__mark {
  width: 38px;
  height: 38px;
  color: var(--accent-warm);
  flex: 0 0 auto;
}

.site-brand__name {
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 2vw, 1.8rem);
  font-weight: 600;
  color: #f3ebe3;
}

.site-brand__tag {
  font-size: 0.82rem;
  color: rgba(239, 231, 222, 0.55);
  letter-spacing: 0.04em;
  margin-top: 2px;
}

.home-hero {
  max-width: 660px;
  margin-bottom: 56px;
}

.home-hero__eyebrow {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(205, 110, 83, 0.95);
  margin-bottom: 14px;
}

.home-hero__title {
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 5vw, 4rem);
  line-height: 1.06;
  letter-spacing: -0.02em;
  font-weight: 500;
  color: #f5eee6;
  margin-bottom: 16px;
}

.home-hero__lead {
  color: rgba(239, 231, 222, 0.62);
  line-height: 1.8;
  font-size: 0.98rem;
}

.home-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 22px;
}

.guide-card {
  position: relative;
  display: block;
  background: rgba(28, 28, 28, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 18px;
  padding: 26px 24px 24px;
  text-decoration: none;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
  overflow: hidden;
}

.guide-card:hover {
  transform: translateY(-3px);
  border-color: rgba(205, 110, 83, 0.55);
  background: rgba(34, 29, 26, 0.98);
}

.guide-card::after {
  content: "";
  position: absolute;
  inset: auto -40px -40px auto;
  width: 140px;
  height: 140px;
  background: radial-gradient(circle, rgba(205, 110, 83, 0.2), transparent 70%);
  pointer-events: none;
}

.guide-card__tag {
  font-family: var(--font-mono);
  font-size: 0.67rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(205, 110, 83, 0.95);
  margin-bottom: 13px;
}

.guide-card__title {
  font-family: var(--font-display);
  font-size: 1.38rem;
  line-height: 1.28;
  color: #f4ece4;
  margin-bottom: 10px;
}

.guide-card__desc {
  font-size: 0.9rem;
  line-height: 1.72;
  color: rgba(239, 231, 222, 0.56);
  margin-bottom: 18px;
}

.guide-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  font-size: 0.74rem;
  color: rgba(239, 231, 222, 0.4);
}

.guide-card__meta-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.guide-card__meta-dot {
  width: 6px;
  height: 6px;
  border-radius: 999px;
  background: var(--ok);
}

.guide-card__arrow {
  position: absolute;
  right: 22px;
  bottom: 22px;
  color: rgba(205, 110, 83, 0.3);
  font-size: 1.15rem;
  transition: transform 0.18s ease, color 0.18s ease;
}

.guide-card:hover .guide-card__arrow {
  color: rgba(205, 110, 83, 0.95);
  transform: translateX(4px);
}

.home-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
  padding-top: 34px;
  margin-top: 72px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  color: rgba(239, 231, 222, 0.42);
  font-size: 0.8rem;
  line-height: 1.8;
}

.home-footer a {
  color: rgba(239, 231, 222, 0.56);
  text-decoration: none;
}

body.page-doc-book {
  background: var(--bg-paper);
  color: var(--text-strong);
  padding: 28px 18px 72px;
}

.book-shell {
  max-width: 1220px;
  margin: 0 auto;
}

.book-topline {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  margin-bottom: 18px;
  padding: 0 10px;
}

.book-topline__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.book-topline__brand .site-brand__mark {
  width: 28px;
  height: 28px;
  color: var(--accent-dark);
}

.book-topline__name {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-strong);
}

.book-topline__tag {
  color: var(--text-soft);
  font-size: 0.72rem;
  margin-top: 2px;
}

.book-topline__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: flex-end;
}

.book-pill-nav {
  display: inline-flex;
  align-items: center;
  padding: 7px 11px;
  border-radius: 999px;
  background: rgba(255, 253, 249, 0.75);
  border: 1px solid rgba(180, 100, 52, 0.12);
  color: var(--text-soft);
  text-decoration: none;
  font-size: 0.74rem;
  line-height: 1;
  transition: transform 0.18s ease, border-color 0.18s ease, color 0.18s ease;
}

.book-pill-nav:hover,
.book-pill-nav.is-active {
  transform: translateY(-1px);
  border-color: rgba(180, 100, 52, 0.24);
  color: var(--accent-dark);
}

.book {
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 10px 0;
}

.page {
  width: 1100px;
  max-width: 100%;
  min-height: 820px;
  margin: 0 auto 28px;
  background: var(--bg-page);
  position: relative;
  padding: 56px 72px 52px;
  border-radius: 16px;
  box-shadow: var(--shadow-page);
  overflow: hidden;
}

.page-num {
  position: absolute;
  bottom: 28px;
  right: 72px;
  font-size: 12px;
  color: #9b9690;
  font-family: var(--font-mono);
}

.page-cover {
  padding: 0;
  min-height: 860px;
}

.page-cover__inner {
  position: relative;
  min-height: 860px;
  padding: 68px 72px 60px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.page-cover--warm {
  background: linear-gradient(180deg, #cd6e53 0%, #c46146 100%);
}

.page-cover--olive {
  background: linear-gradient(180deg, #748760 0%, #5f7350 100%);
}

.page-cover--blue {
  background: linear-gradient(180deg, #68829e 0%, #526a86 100%);
}

.page-cover__eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(36, 29, 20, 0.74);
}

.page-cover__title {
  font-family: var(--font-display);
  font-size: clamp(3.2rem, 7vw, 4.9rem);
  line-height: 0.98;
  letter-spacing: -0.03em;
  color: #1a0f0f;
  font-weight: 500;
  max-width: 760px;
}

.page-cover__summary {
  max-width: 680px;
  color: rgba(26, 15, 15, 0.78);
  font-size: 1.02rem;
  line-height: 1.82;
}

.page-cover__footer {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 18px;
}

.page-cover__brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.page-cover__brand .site-brand__mark {
  width: 54px;
  height: 54px;
  color: #1a0f0f;
}

.page-cover__brand-name {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 600;
  color: #1a0f0f;
}

.page-cover__brand-sub {
  color: rgba(26, 15, 15, 0.66);
  font-size: 0.78rem;
  margin-top: 2px;
}

.page-cover__meta {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: rgba(26, 15, 15, 0.68);
  text-align: right;
  line-height: 1.8;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1.5px solid var(--text-strong);
  border-radius: 999px;
  padding: 5px 14px;
  font-size: 12px;
  font-family: var(--font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 16px;
  color: var(--text-strong);
}

.page-title {
  font-family: var(--font-display);
  font-size: 3.2rem;
  line-height: 1.02;
  font-weight: 500;
  color: var(--text-strong);
  margin-bottom: 24px;
}

.page-intro {
  font-size: 0.98rem;
  line-height: 1.8;
  color: var(--text-body);
  max-width: 72ch;
  margin-bottom: 18px;
}

.meta-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 20px;
}

.meta-box {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px 16px;
  background: var(--bg-page-soft);
}

.meta-box__label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
}

.meta-box__value {
  color: var(--text-body);
  font-size: 0.88rem;
  line-height: 1.65;
}

.toc-list {
  margin-top: 22px;
  display: grid;
  gap: 10px;
}

.toc-row {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: baseline;
  text-decoration: none;
  color: inherit;
}

.toc-row__label {
  font-size: 0.92rem;
  line-height: 1.6;
  color: var(--text-body);
}

.toc-row__dots {
  flex: 1;
  border-bottom: 1.5px dotted #c5bbb0;
  margin: 0 8px 4px;
}

.toc-row__page {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-soft);
}

.chapter-page {
  display: grid;
  gap: 16px;
}

.chapter-page__header {
  border-bottom: 1px solid var(--line);
  padding-bottom: 14px;
  margin-bottom: 2px;
}

.chapter-page__eyebrow {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}

.chapter-page__title {
  font-family: var(--font-display);
  font-size: 2.1rem;
  line-height: 1.08;
  font-weight: 600;
  color: var(--text-strong);
  margin-bottom: 10px;
}

.chapter-page__summary {
  color: var(--text-soft);
  font-size: 0.92rem;
  line-height: 1.72;
}

.doc-content {
  color: var(--text-body);
}

.doc-content > * + * {
  margin-top: 1rem;
}

.doc-content p,
.doc-content li {
  font-size: 0.96rem;
  line-height: 1.82;
  color: var(--text-body);
}

.doc-content p {
  margin-bottom: 0.88rem;
}

.doc-content ul,
.doc-content ol {
  margin: 0.2rem 0 1.08rem 1.25rem;
}

.doc-content a {
  color: var(--accent-dark);
}

.doc-content h1,
.doc-content h2,
.doc-content h3,
.doc-content h4,
.doc-content .chapter-title,
.doc-content .section-title,
.doc-content .ptitle,
.doc-content .hero-title,
.doc-content .ch-title {
  font-family: var(--font-display);
  color: var(--text-strong);
  line-height: 1.16;
  letter-spacing: -0.02em;
}

.doc-content h1,
.doc-content .ptitle {
  font-size: clamp(2rem, 3vw, 3rem) !important;
  margin: 0 0 1rem;
  font-weight: 500;
}

.doc-content h2,
.doc-content .chapter-title,
.doc-content .section-title,
.doc-content .ch-title {
  font-size: clamp(1.4rem, 2vw, 2rem) !important;
  margin: 2.1rem 0 0.75rem;
  font-weight: 600;
}

.doc-content h3,
.doc-content h4,
.doc-content .lesson-title,
.doc-content .concept-term {
  font-size: 1.06rem !important;
  margin: 1.45rem 0 0.48rem;
  font-weight: 600;
}

.doc-content .ch-num,
.doc-content .ch-subtitle,
.doc-content .section-label,
.doc-content .card-tag,
.doc-content .hero-kicker,
.doc-content .lesson-num,
.doc-content .rule-label,
.doc-content .nav-num,
.doc-content .chapter-tag,
.doc-content .chapter-label,
.doc-content .hero-tag {
  font-family: var(--font-mono) !important;
  font-size: 0.68rem !important;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent) !important;
}

.doc-content .chapter,
.doc-content .content-section {
  margin-bottom: 2.6rem;
}

.doc-content .ch-header,
.doc-content .chapter-header,
.doc-content .section-label {
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.55rem;
}

.doc-content .callout,
.doc-content .rule-box,
.doc-content .exercise-block,
.doc-content .lesson-card,
.doc-content .notebox,
.doc-content .ptb,
.doc-content .solbox,
.doc-content .strategy-item,
.doc-content .concept-item,
.doc-content .warn-box,
.doc-content .eval-component,
.doc-content .metric-card {
  background: var(--bg-page-soft);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px 18px 15px;
}

.doc-content .lesson-card + .lesson-card,
.doc-content .exercise-block + .exercise-block,
.doc-content .callout + .callout {
  margin-top: 1rem;
}

.doc-content .strategy-grid,
.doc-content .concept-grid,
.doc-content .lesson-grid,
.doc-content .tag-list,
.doc-content .course-meta,
.doc-content .eval-component-grid {
  display: grid;
  gap: 14px;
}

.doc-content .strategy-grid,
.doc-content .concept-grid,
.doc-content .eval-component-grid {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin: 1.15rem 0;
}

.doc-content .tag-list,
.doc-content .course-meta {
  grid-template-columns: repeat(auto-fit, minmax(140px, max-content));
}

.doc-content .tag,
.doc-content .hero-badge,
.doc-content .badge,
.doc-content .ex-num {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(180, 100, 52, 0.08);
  border: 1px solid rgba(180, 100, 52, 0.14);
  color: var(--accent-dark);
  font-size: 0.74rem !important;
  line-height: 1;
}

.doc-content .tag,
.doc-content .hero-badge,
.doc-content .lesson-tags {
  font-family: var(--font-body);
}

.doc-content .lesson-header,
.doc-content .ex-header,
.doc-content .meta-item,
.doc-content .hero-meta,
.doc-content .topbar-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-bottom: 0.88rem;
}

.doc-content .prompt-demo,
.doc-content .pa-item,
.doc-content .flow-step,
.doc-content .arch-row {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr);
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.doc-content .prompt-demo:last-child,
.doc-content .pa-item:last-child,
.doc-content .flow-step:last-child,
.doc-content .arch-row:last-child {
  border-bottom: none;
}

.doc-content .strategy-num,
.doc-content .pa-num,
.doc-content .flow-num,
.doc-content .callout-icon,
.doc-content .arch-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 999px;
  background: rgba(180, 100, 52, 0.09);
  color: var(--accent-dark);
  border: 1px solid rgba(180, 100, 52, 0.14);
  font-family: var(--font-mono);
  font-size: 0.74rem;
}

.doc-content .example-block,
.doc-content .code-wrap,
.doc-content .table-wrap {
  margin: 1rem 0 1.2rem;
}

.doc-content .example-label,
.doc-content .pd-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-soft);
  background: var(--bg-page-soft);
  border: 1px solid var(--line);
  border-bottom: none;
  padding: 8px 14px;
  border-radius: 10px 10px 0 0;
}

.doc-content pre,
.doc-content .code-wrap pre {
  overflow-x: auto;
  background: var(--code-bg);
  border-radius: 0 0 10px 10px;
  border: 1px solid #16110c;
  padding: 18px 18px 20px;
}

.doc-content code,
.doc-content pre code {
  font-family: var(--font-mono);
}

.doc-content pre code {
  font-size: 0.82rem;
  line-height: 1.75;
  color: var(--code-text);
}

.doc-content :not(pre) > code {
  background: rgba(180, 100, 52, 0.08);
  border: 1px solid rgba(180, 100, 52, 0.14);
  border-radius: 6px;
  padding: 2px 6px;
  color: var(--accent-dark);
  font-size: 0.82em;
}

.copy-btn {
  position: absolute;
  top: 10px;
  right: 12px;
  z-index: 2;
  background: rgba(180, 100, 52, 0.18);
  border: 1px solid rgba(180, 100, 52, 0.3);
  color: var(--code-text);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  border-radius: 8px;
  padding: 5px 10px;
  cursor: pointer;
}

.doc-content table,
.doc-content .fmt-table,
.doc-content .ctable,
.doc-content .atable {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.4rem;
}

.doc-content th,
.doc-content td {
  border: 1px solid var(--line);
  padding: 9px 12px;
  vertical-align: top;
  text-align: left;
}

.doc-content th {
  background: var(--bg-page-soft);
  color: var(--text-strong);
  font-weight: 600;
}

.doc-content blockquote {
  margin: 1.2rem 0;
  padding: 16px 18px;
  border-left: 4px solid var(--accent);
  background: rgba(180, 100, 52, 0.05);
  border-radius: 0 10px 10px 0;
}

.doc-content .book {
  display: grid;
  gap: 24px;
}

.doc-content .page {
  width: auto !important;
  min-height: 0 !important;
  margin: 0 !important;
  padding: clamp(22px, 3vw, 34px) !important;
  background: rgba(255, 253, 249, 0.96) !important;
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: none !important;
}

.doc-content .page-num {
  position: static !important;
  display: block;
  margin-top: 18px;
  text-align: right;
  color: var(--text-soft) !important;
  font-family: var(--font-mono);
}

.doc-content .two-col {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.book-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
  margin: 4px auto 0;
  padding: 0 10px;
  color: var(--text-soft);
  font-size: 0.78rem;
  line-height: 1.8;
}

.book-footer a {
  color: var(--accent-dark);
  text-decoration: none;
}

@media (max-width: 980px) {
  .book-topline {
    flex-direction: column;
    align-items: flex-start;
  }

  .book-topline__nav {
    justify-content: flex-start;
  }

  .page {
    padding: 28px 24px 56px;
    min-height: 0;
  }

  .page-num {
    right: 24px;
  }

  .page-cover__inner {
    padding: 42px 28px 56px;
    min-height: 0;
  }
}

@media (max-width: 760px) {
  body.page-home {
    padding: 34px 18px 56px;
  }

  body.page-doc-book {
    padding: 22px 10px 48px;
  }

  .doc-content .two-col,
  .doc-content .prompt-demo,
  .doc-content .pa-item,
  .doc-content .flow-step,
  .doc-content .arch-row,
  .meta-grid {
    grid-template-columns: 1fr;
  }

  .home-grid,
  .doc-content .strategy-grid,
  .doc-content .concept-grid,
  .doc-content .eval-component-grid {
    grid-template-columns: 1fr;
  }

  .page-title {
    font-size: 2.3rem;
  }
}