:root {
  color-scheme: light;
  --bg: #f5f4ef;
  --paper: #fffef9;
  --ink: #111827;
  --muted: #667085;
  --faint: #8d94a3;
  --line: #deded7;
  --line-soft: #ebeae3;
  --navy: #0d1426;
  --navy-2: #151f37;
  --mint: #91edc9;
  --mint-deep: #116b53;
  --coral: #ff7657;
  --blue: #5673ff;
  --code: #101827;
  --shadow: 0 18px 60px rgba(26, 32, 44, .09);
  --header-h: 68px;
  --radius: 18px;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0d1220;
  --paper: #141b2b;
  --ink: #edf1f7;
  --muted: #a4adbd;
  --faint: #7d8799;
  --line: #30394b;
  --line-soft: #242d3f;
  --navy: #080d17;
  --navy-2: #111a2c;
  --mint-deep: #90edc9;
  --code: #080d17;
  --shadow: 0 20px 70px rgba(0, 0, 0, .28);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 24px); }
body { margin: 0; background: var(--bg); color: var(--ink); font-size: 16px; line-height: 1.7; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
button { color: inherit; }
.container { width: min(1180px, calc(100% - 48px)); margin-inline: auto; }
.eyebrow { margin: 0 0 12px; color: var(--mint-deep); font-size: 11px; font-weight: 800; letter-spacing: .16em; text-transform: uppercase; }

.site-header { position: sticky; z-index: 50; top: 0; height: var(--header-h); padding: 0 28px; display: flex; align-items: center; justify-content: space-between; background: color-mix(in srgb, var(--paper) 88%, transparent); border-bottom: 1px solid var(--line-soft); backdrop-filter: blur(18px); }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 850; letter-spacing: -.03em; }
.brand-mark { width: 34px; height: 34px; display: grid; place-items: center; border-radius: 10px; color: var(--navy); background: var(--mint); font-family: Georgia, serif; font-size: 20px; }
.brand small { margin-left: 3px; color: var(--faint); font-size: 10px; font-weight: 750; letter-spacing: .12em; text-transform: uppercase; }
.header-actions { display: flex; align-items: center; gap: 8px; }
.search-trigger { width: 240px; height: 40px; padding: 0 8px 0 14px; display: flex; align-items: center; justify-content: space-between; color: var(--muted); background: var(--bg); border: 1px solid var(--line); border-radius: 11px; cursor: pointer; font-size: 13px; }
kbd { padding: 2px 7px; color: var(--faint); background: var(--paper); border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 6px; font-size: 10px; }
.icon-button { width: 40px; height: 40px; display: grid; place-items: center; background: transparent; border: 1px solid var(--line); border-radius: 11px; cursor: pointer; }
.moon { display: none; }
[data-theme="dark"] .moon { display: inline; }
[data-theme="dark"] .sun { display: none; }
.mobile-only { display: none; }
.reading-progress { position: fixed; z-index: 90; top: 0; left: 0; right: 0; height: 3px; pointer-events: none; }
.reading-progress span { display: block; width: 0; height: 100%; background: linear-gradient(90deg, var(--mint), var(--coral)); }

.home-hero { position: relative; min-height: 680px; display: flex; align-items: center; overflow: hidden; color: #f7f9fc; background: var(--navy); }
.hero-grid { position: absolute; inset: 0; opacity: .26; background-image: linear-gradient(rgba(255,255,255,.1) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.1) 1px, transparent 1px); background-size: 68px 68px; mask-image: linear-gradient(to right, black, transparent 84%); }
.home-hero::before { content: ""; position: absolute; width: 500px; height: 500px; right: -40px; top: 40px; border: 1px solid rgba(145,237,201,.24); border-radius: 50%; box-shadow: 0 0 0 90px rgba(145,237,201,.025), 0 0 0 180px rgba(145,237,201,.018); }
.home-hero::after { content: "L"; position: absolute; right: 8%; bottom: -90px; color: transparent; -webkit-text-stroke: 1px rgba(255,255,255,.06); font: 700 460px/1 Georgia, serif; }
.hero-inner { position: relative; z-index: 1; padding-block: 82px 60px; }
.hero-label { margin: 0 0 24px; color: #aeb8ca; font-size: 12px; font-weight: 700; letter-spacing: .13em; text-transform: uppercase; }
.hero-label span { width: 30px; height: 1px; display: inline-block; margin-right: 10px; vertical-align: middle; background: var(--mint); }
.home-hero h1 { max-width: 920px; margin: 0; font-size: clamp(52px, 7vw, 92px); line-height: 1.02; letter-spacing: -.065em; }
.home-hero h1 strong { color: var(--mint); font-weight: 750; }
.hero-copy { max-width: 690px; margin: 28px 0 34px; color: #b8c0ce; font-size: 18px; line-height: 1.8; }
.hero-actions { display: flex; gap: 12px; }
.primary-button, .secondary-button { min-height: 48px; padding: 0 20px; display: inline-flex; align-items: center; justify-content: center; gap: 28px; border-radius: 12px; font-weight: 750; cursor: pointer; }
.primary-button { color: var(--navy); background: var(--mint); border: 1px solid var(--mint); }
.primary-button:hover { transform: translateY(-1px); box-shadow: 0 9px 25px rgba(145,237,201,.2); }
.secondary-button { color: inherit; background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.2); }
.secondary-button kbd { color: #aeb8ca; background: rgba(255,255,255,.08); border-color: rgba(255,255,255,.16); }
.hero-stats { margin-top: 60px; display: flex; gap: 54px; }
.hero-stats div { display: flex; flex-direction: column; }
.hero-stats b { color: #fff; font-size: 26px; line-height: 1.2; }
.hero-stats span { color: #8490a5; font-size: 12px; }

.learning-path, .topic-section { padding-block: 100px; }
.section-heading { margin-bottom: 42px; display: grid; grid-template-columns: 1fr 1fr; align-items: end; gap: 60px; }
.section-heading h2 { margin: 0; font-size: clamp(34px, 4vw, 52px); line-height: 1.1; letter-spacing: -.045em; }
.section-heading > p { max-width: 540px; margin: 0; color: var(--muted); }
.path-track { position: relative; display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.path-track a { position: relative; min-height: 210px; padding: 34px 24px 24px 0; border-right: 1px solid var(--line); }
.path-track a:last-child { border-right: 0; padding-left: 24px; }
.path-track a:not(:first-child):not(:last-child) { padding-left: 24px; }
.path-track a::before { content: ""; position: absolute; width: 9px; height: 9px; top: -5px; left: 0; background: var(--coral); border-radius: 50%; box-shadow: 0 0 0 6px var(--bg); }
.path-track a:not(:first-child)::before { left: 24px; }
.path-track small { color: var(--coral); font-size: 11px; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.path-track h3 { margin: 16px 0 7px; font-size: 21px; }
.path-track p { margin: 0; color: var(--muted); font-size: 14px; }
.path-track a:hover h3 { color: var(--mint-deep); }
.topic-section { padding-top: 30px; }
.topic-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.topic-card { min-height: 235px; padding: 24px; display: grid; grid-template-columns: 1fr auto; grid-template-rows: auto auto auto 1fr auto; background: var(--paper); border: 1px solid var(--line-soft); border-radius: var(--radius); transition: .22s ease; }
.topic-card:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--mint-deep) 45%, var(--line)); box-shadow: var(--shadow); }
.topic-number { color: var(--faint); font: 600 11px/1 monospace; }
.topic-icon { width: 38px; height: 38px; grid-row: span 2; display: grid; place-items: center; color: var(--navy); background: var(--mint); border-radius: 11px; font: 700 16px/1 Georgia, serif; }
.topic-card > p { margin: 21px 0 2px; color: var(--mint-deep); font-size: 10px; font-weight: 850; letter-spacing: .11em; text-transform: uppercase; }
.topic-card h3 { margin: 0; font-size: 21px; line-height: 1.3; letter-spacing: -.025em; }
.topic-card small { grid-column: 1 / -1; align-self: start; margin-top: 12px; color: var(--muted); line-height: 1.55; }
.topic-card div { grid-column: 1 / -1; align-self: end; display: flex; justify-content: space-between; color: var(--faint); font-size: 12px; }
.topic-card div b { color: var(--ink); }
.principles { margin-block: 60px 110px; padding: 70px; display: grid; grid-template-columns: 1fr 1.2fr; gap: 90px; color: #edf3f9; background: var(--navy); border-radius: 30px; }
.principles h2 { margin: 0; font-size: 44px; line-height: 1.15; letter-spacing: -.045em; }
.principle-list { border-top: 1px solid rgba(255,255,255,.16); }
.principle-list p { margin: 0; padding: 20px 0; display: grid; grid-template-columns: 36px 140px 1fr; border-bottom: 1px solid rgba(255,255,255,.16); color: #9ba7b9; }
.principle-list p span { color: var(--coral); font: 700 12px/1.7 monospace; }
.principle-list p b { color: #f4f7fb; }

.site-footer { min-height: 160px; padding: 42px max(32px, calc((100vw - 1180px) / 2)); display: flex; justify-content: space-between; align-items: flex-start; gap: 60px; color: #9aa5b8; background: var(--navy); border-top: 1px solid rgba(255,255,255,.08); }
.site-footer div { display: flex; flex-direction: column; }
.site-footer strong { color: #fff; font-size: 20px; }
.site-footer span { font-size: 12px; }
.site-footer p { max-width: 620px; margin: 0; font-size: 12px; text-align: right; }

.section-page { padding-block: 44px 90px; }
.breadcrumb { display: flex; align-items: center; gap: 9px; color: var(--faint); font-size: 12px; }
.breadcrumb a:hover { color: var(--mint-deep); }
.section-hero { margin: 34px 0 54px; padding: 54px; display: grid; grid-template-columns: auto 1fr; gap: 32px; color: #eef3fa; background: var(--navy); border-radius: 26px; overflow: hidden; }
.section-glyph { width: 78px; height: 78px; display: grid; place-items: center; color: var(--navy); background: var(--mint); border-radius: 20px; font: 700 30px/1 Georgia, serif; }
.section-hero h1 { margin: 2px 0 8px; font-size: clamp(40px, 6vw, 72px); line-height: 1; letter-spacing: -.055em; }
.section-hero p:not(.eyebrow) { max-width: 620px; margin: 0; color: #a8b2c3; }
.section-hero span { display: inline-block; margin-top: 18px; color: #758299; font-size: 12px; }
.lesson-list { background: var(--paper); border: 1px solid var(--line-soft); border-radius: var(--radius); overflow: hidden; }
.lesson-row { min-height: 112px; padding: 20px 24px; display: grid; grid-template-columns: 48px 1fr 70px 20px; align-items: center; gap: 18px; border-bottom: 1px solid var(--line-soft); }
.lesson-row:last-child { border-bottom: 0; }
.lesson-row:hover { background: color-mix(in srgb, var(--mint) 8%, var(--paper)); }
.lesson-index { color: var(--faint); font: 600 12px/1 monospace; }
.lesson-row h3 { margin: 0 0 3px; font-size: 17px; letter-spacing: -.015em; }
.lesson-row p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.5; }
.lesson-row small { color: var(--faint); text-align: right; }
.lesson-row b { color: var(--mint-deep); }

.docs-layout { min-height: calc(100vh - var(--header-h)); display: grid; grid-template-columns: 274px minmax(0, 1fr) 228px; }
.docs-sidebar { position: sticky; top: var(--header-h); height: calc(100vh - var(--header-h)); border-right: 1px solid var(--line-soft); background: color-mix(in srgb, var(--paper) 60%, var(--bg)); }
.sidebar-scroll { height: 100%; padding: 24px 16px 40px; overflow-y: auto; scrollbar-width: thin; }
.section-nav, .doc-nav { display: flex; flex-direction: column; gap: 3px; }
.section-link { min-height: 38px; padding: 5px 8px; display: grid; grid-template-columns: 25px 1fr auto; align-items: center; gap: 6px; color: var(--muted); border-radius: 9px; font-size: 12px; }
.section-link > span { width: 24px; height: 24px; display: grid; place-items: center; color: var(--ink); background: var(--line-soft); border-radius: 7px; font: 700 10px/1 Georgia, serif; }
.section-link b { overflow: hidden; font-weight: 650; text-overflow: ellipsis; white-space: nowrap; }
.section-link small { color: var(--faint); }
.section-link:hover, .section-link.is-current { color: var(--ink); background: var(--paper); }
.section-link.is-current > span { color: var(--navy); background: var(--mint); }
.current-section { margin-top: 28px; padding-top: 22px; border-top: 1px solid var(--line); }
.doc-link { padding: 7px 9px; color: var(--muted); border-left: 2px solid transparent; font-size: 12px; line-height: 1.45; }
.doc-link:hover { color: var(--ink); }
.doc-link.is-active { color: var(--ink); background: color-mix(in srgb, var(--mint) 12%, transparent); border-color: var(--mint-deep); border-radius: 0 8px 8px 0; font-weight: 700; }
.doc-main { min-width: 0; }
.article-card { width: min(850px, calc(100% - 70px)); margin: 0 auto; padding: 42px 0 100px; }
.article-header { padding: 54px 0 35px; border-bottom: 1px solid var(--line); }
.article-kicker { margin: 0 0 12px; color: var(--coral); font-size: 11px; font-weight: 850; letter-spacing: .15em; text-transform: uppercase; }
.article-header h1 { margin: 0; font-size: clamp(38px, 4.5vw, 64px); line-height: 1.08; letter-spacing: -.05em; }
.article-deck { max-width: 720px; margin: 22px 0 0; color: var(--muted); font-size: 17px; }
.article-meta { margin-top: 24px; display: flex; flex-wrap: wrap; gap: 8px; }
.meta-pill { padding: 5px 10px; color: var(--muted); background: var(--paper); border: 1px solid var(--line); border-radius: 999px; font-size: 10px; font-weight: 700; }
.meta-pill.accent { color: var(--mint-deep); border-color: color-mix(in srgb, var(--mint-deep) 28%, var(--line)); }
.article-summary { margin: 32px 0 48px; padding: 20px 22px; display: grid; grid-template-columns: 64px 1fr; gap: 15px; background: color-mix(in srgb, var(--mint) 12%, var(--paper)); border: 1px solid color-mix(in srgb, var(--mint-deep) 24%, var(--line)); border-radius: 14px; }
.article-summary span { color: var(--mint-deep); font: 800 11px/1.8 monospace; letter-spacing: .08em; }
.article-summary p { margin: 0; color: var(--muted); font-size: 14px; }
.article-content { color: color-mix(in srgb, var(--ink) 92%, var(--muted)); font-size: 16px; line-height: 1.9; }
.article-content h2 { margin: 64px 0 18px; padding-top: 6px; font-size: 31px; line-height: 1.3; letter-spacing: -.035em; }
.article-content h3 { margin: 44px 0 15px; font-size: 23px; line-height: 1.4; letter-spacing: -.025em; }
.article-content h4 { margin: 32px 0 12px; font-size: 18px; }
.article-content p { margin: 0 0 20px; }
.article-content a { color: var(--blue); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; }
.article-content strong { color: var(--ink); font-weight: 750; }
.article-content ul, .article-content ol { margin: 14px 0 22px; padding-left: 25px; }
.article-content li { margin: 7px 0; padding-left: 4px; }
.article-content li::marker { color: var(--mint-deep); font-weight: 700; }
.article-content blockquote { margin: 28px 0; padding: 20px 24px; color: var(--muted); background: color-mix(in srgb, var(--blue) 5%, var(--paper)); border-left: 3px solid var(--blue); border-radius: 0 12px 12px 0; }
.article-content blockquote p:last-child { margin-bottom: 0; }
.article-content img { max-width: 100%; height: auto; margin: 22px auto; display: block; background: var(--paper); border: 1px solid var(--line-soft); border-radius: 12px; box-shadow: var(--shadow); }
.article-content code { padding: .12em .38em; color: color-mix(in srgb, var(--coral) 78%, var(--ink)); background: color-mix(in srgb, var(--coral) 8%, var(--paper)); border: 1px solid color-mix(in srgb, var(--coral) 16%, var(--line)); border-radius: 5px; font: 500 .88em/1.6 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
.codehilite { position: relative; margin: 28px 0; background: var(--code); border: 1px solid #26334b; border-radius: 14px; overflow: hidden; }
.codehilite::before { content: ""; height: 38px; display: block; background: radial-gradient(circle at 18px 19px,#ff6b61 0 4px,transparent 5px),radial-gradient(circle at 33px 19px,#ffc34a 0 4px,transparent 5px),radial-gradient(circle at 48px 19px,#57cc75 0 4px,transparent 5px); border-bottom: 1px solid #26334b; }
.codehilite pre { margin: 0; padding: 20px 22px 24px; overflow-x: auto; color: #dce5f3; font: 500 13px/1.75 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; tab-size: 2; }
.codehilite code { padding: 0; color: inherit; background: transparent; border: 0; }
.copy-code { position: absolute; top: 7px; right: 8px; height: 25px; padding: 0 9px; color: #9ba8bb; background: #182238; border: 1px solid #2a3852; border-radius: 6px; cursor: pointer; font-size: 10px; }
.table-wrap { max-width: 100%; margin: 26px 0; border: 1px solid var(--line); border-radius: 12px; overflow-x: auto; }
.article-content table { width: 100%; border-collapse: collapse; background: var(--paper); font-size: 13px; line-height: 1.55; }
.article-content th, .article-content td { min-width: 110px; padding: 12px 14px; text-align: left; border-bottom: 1px solid var(--line-soft); border-right: 1px solid var(--line-soft); vertical-align: top; }
.article-content th { color: var(--ink); background: color-mix(in srgb, var(--mint) 8%, var(--paper)); font-weight: 750; }
.article-content tr:last-child td { border-bottom: 0; }
.article-note { margin: 70px 0 20px; padding: 18px 20px; display: grid; grid-template-columns: 82px 1fr; color: var(--muted); background: var(--paper); border: 1px solid var(--line); border-radius: 12px; font-size: 12px; }
.article-note strong { color: var(--ink); }
.article-note p { margin: 0; }
.doc-pager { margin-top: 28px; padding-top: 24px; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; border-top: 1px solid var(--line); }
.doc-pager a { min-height: 88px; padding: 15px 17px; display: flex; flex-direction: column; justify-content: center; background: var(--paper); border: 1px solid var(--line-soft); border-radius: 12px; }
.doc-pager a:hover { border-color: var(--mint-deep); }
.doc-pager a.next { text-align: right; }
.doc-pager small { color: var(--faint); font-size: 10px; }
.doc-pager span { font-size: 13px; font-weight: 700; }
.page-toc { position: sticky; top: var(--header-h); height: calc(100vh - var(--header-h)); padding: 30px 20px; border-left: 1px solid var(--line-soft); overflow-y: auto; }
.page-toc nav { display: flex; flex-direction: column; }
.page-toc a { padding: 5px 0 5px 10px; color: var(--faint); border-left: 1px solid var(--line); font-size: 11px; line-height: 1.45; }
.page-toc a:hover, .page-toc a.is-visible { color: var(--ink); border-color: var(--mint-deep); }
.page-toc .toc-depth-1 { padding-left: 20px; }
.page-toc .toc-depth-2 { padding-left: 30px; }
.toc-empty { color: var(--faint); font-size: 11px; }

.search-modal[hidden] { display: none; }
.search-modal { position: fixed; z-index: 100; inset: 0; display: grid; place-items: start center; padding-top: min(14vh, 120px); }
.search-backdrop { position: absolute; inset: 0; background: rgba(5, 9, 17, .7); backdrop-filter: blur(5px); }
.search-panel { position: relative; width: min(700px, calc(100% - 32px)); max-height: min(680px, 76vh); display: flex; flex-direction: column; background: var(--paper); border: 1px solid var(--line); border-radius: 18px; box-shadow: 0 30px 100px rgba(0,0,0,.28); overflow: hidden; }
.search-input-wrap { min-height: 64px; padding: 0 17px; display: grid; grid-template-columns: 28px 1fr auto; align-items: center; border-bottom: 1px solid var(--line); }
.search-input-wrap > span { color: var(--mint-deep); font-size: 24px; }
.search-input-wrap input { width: 100%; height: 62px; color: var(--ink); background: transparent; border: 0; outline: 0; font-size: 16px; }
.search-results { min-height: 160px; padding: 9px; overflow-y: auto; }
.search-empty { padding: 50px 20px; color: var(--faint); text-align: center; font-size: 13px; }
.search-result { padding: 13px 14px; display: grid; grid-template-columns: 1fr auto; gap: 4px 20px; border-radius: 10px; }
.search-result:hover, .search-result.is-selected { background: color-mix(in srgb, var(--mint) 12%, var(--bg)); }
.search-result h3 { margin: 0; font-size: 14px; }
.search-result p { margin: 0; color: var(--muted); font-size: 11px; line-height: 1.5; }
.search-result span { grid-row: 1 / 3; grid-column: 2; align-self: center; color: var(--faint); font-size: 10px; }
.not-found { min-height: calc(100vh - var(--header-h)); padding: 13vh 30px; text-align: center; }
.not-found h1 { margin: 8px 0; font-size: clamp(42px, 7vw, 82px); letter-spacing: -.055em; }
.not-found > p:not(.eyebrow) { color: var(--muted); }
.not-found > div { display: flex; justify-content: center; gap: 10px; margin-top: 28px; }
.not-found .secondary-button { color: var(--ink); border-color: var(--line); }

.codehilite .hll { background-color: #2a3550 }
.codehilite .c, .codehilite .ch, .codehilite .cm, .codehilite .cp, .codehilite .cpf, .codehilite .c1, .codehilite .cs { color: #71809c; font-style: italic }
.codehilite .k, .codehilite .kc, .codehilite .kd, .codehilite .kn, .codehilite .kp, .codehilite .kr, .codehilite .kt { color: #c792ea }
.codehilite .s, .codehilite .sa, .codehilite .sb, .codehilite .sc, .codehilite .dl, .codehilite .sd, .codehilite .s2, .codehilite .se, .codehilite .sh, .codehilite .si, .codehilite .sx, .codehilite .sr, .codehilite .s1, .codehilite .ss { color: #c3e88d }
.codehilite .m, .codehilite .mb, .codehilite .mf, .codehilite .mh, .codehilite .mi, .codehilite .mo, .codehilite .il { color: #f78c6c }
.codehilite .na, .codehilite .nb, .codehilite .nc, .codehilite .no, .codehilite .nd, .codehilite .ni, .codehilite .ne, .codehilite .nf, .codehilite .nl, .codehilite .nn, .codehilite .nt, .codehilite .nv { color: #82aaff }
.codehilite .o, .codehilite .ow, .codehilite .p { color: #89ddff }

@media (max-width: 1180px) {
  .docs-layout { grid-template-columns: 250px minmax(0, 1fr); }
  .page-toc { display: none; }
  .topic-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 820px) {
  .container { width: min(100% - 30px, 680px); }
  .site-header { padding: 0 15px; }
  .brand small, .search-trigger span, .search-trigger kbd { display: none; }
  .search-trigger { width: 40px; padding: 0; justify-content: center; }
  .search-trigger::after { content: "⌕"; font-size: 20px; }
  .mobile-only { display: grid; }
  .home-hero { min-height: 650px; }
  .hero-inner { padding-top: 64px; }
  .hero-copy { font-size: 16px; }
  .hero-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
  .section-heading { grid-template-columns: 1fr; gap: 18px; }
  .path-track { grid-template-columns: 1fr 1fr; }
  .path-track a { padding-left: 0 !important; border-bottom: 1px solid var(--line); }
  .path-track a::before { left: 0 !important; }
  .topic-grid { grid-template-columns: 1fr; }
  .principles { padding: 38px 26px; grid-template-columns: 1fr; gap: 40px; }
  .principles h2 { font-size: 34px; }
  .principle-list p { grid-template-columns: 30px 1fr; }
  .principle-list p b { grid-column: 2; }
  .site-footer { flex-direction: column; gap: 18px; }
  .site-footer p { text-align: left; }
  .section-hero { padding: 35px 26px; grid-template-columns: 1fr; }
  .lesson-row { grid-template-columns: 36px 1fr 15px; }
  .lesson-row small { display: none; }
  .docs-layout { display: block; }
  .docs-sidebar { position: fixed; z-index: 45; top: var(--header-h); left: 0; width: min(320px, 88vw); transform: translateX(-105%); transition: transform .25s ease; box-shadow: var(--shadow); }
  body.nav-open .docs-sidebar { transform: translateX(0); }
  .article-card { width: min(100% - 32px, 720px); padding-top: 25px; }
  .article-header { padding-top: 38px; }
  .article-summary { grid-template-columns: 1fr; }
  .doc-pager { grid-template-columns: 1fr; }
}

@media (max-width: 520px) {
  .home-hero h1 { font-size: 47px; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-stats { margin-top: 40px; }
  .path-track { grid-template-columns: 1fr; border-top: 0; }
  .path-track a { border-top: 1px solid var(--line); border-right: 0; }
  .section-hero h1 { font-size: 42px; }
  .lesson-row { padding-inline: 14px; gap: 10px; }
  .lesson-row p { display: none; }
  .article-header h1 { font-size: 38px; }
  .article-content { font-size: 15px; }
  .article-content h2 { font-size: 27px; }
  .article-content h3 { font-size: 21px; }
}

@media print {
  .site-header, .docs-sidebar, .page-toc, .reading-progress, .search-modal, .doc-pager, .site-footer { display: none !important; }
  .docs-layout { display: block; }
  .article-card { width: 100%; padding: 0; }
  body { background: white; color: black; }
}