/* Labook · A quiet reading room for building agents. */
:root {
  color-scheme: light;
  --paper: #ffffff;
  --canvas: #f8f9fc;
  --ink: #202943;
  --muted: #67718a;
  --faint: #9099ad;
  --line: #e3e7ef;
  --accent: #3447b0;
  --accent-hover: #28388f;
  --accent-soft: #eeeffb;
  --green: #437c74;
  --code: #f2f4f8;
  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", STSong, "SimSun", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-family: var(--sans);
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  scroll-padding-top: 104px;
}

*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; background: var(--paper); color: var(--ink); }
body[data-theme="dark"] {
  color-scheme: dark;
  --paper: #171d2b;
  --canvas: #1b2232;
  --ink: #e1e6f2;
  --muted: #a1aec7;
  --faint: #7d8aa4;
  --line: #303b51;
  --accent: #a3afff;
  --accent-hover: #c0c8ff;
  --accent-soft: #2a3456;
  --green: #90beb5;
  --code: #222b3d;
}
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
button { color: inherit; cursor: pointer; }
button, input, a { -webkit-tap-highlight-color: transparent; }
button { border: 0; }
button:disabled { cursor: default; opacity: .55; }
button, a, input { touch-action: manipulation; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 5px; }
::selection { background: var(--accent-soft); color: var(--ink); }
img { max-width: 100%; height: auto; }
svg { flex-shrink: 0; vertical-align: middle; }
[hidden] { display: none !important; }
.skip-link { position: fixed; top: 12px; left: 16px; z-index: 100; padding: 12px 20px; background: var(--accent); color: var(--paper); transform: translateY(-160%); }
.skip-link:focus { transform: none; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: 28px;
  min-height: 84px;
  padding: 0 max(32px, calc((100vw - 1260px) / 2));
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}
.brand { display: inline-flex; flex: 0 0 auto; align-items: center; gap: 11px; }
.brand-icon { display: grid; place-items: center; width: 35px; height: 35px; border-radius: 9px 2px 9px 2px; color: #fff; background: #3447b0; font-family: var(--serif); font-size: 21px; }
.brand-icon svg { width: 21px; height: 21px; }
.brand-name { font-size: 21px; font-weight: 650; letter-spacing: -.6px; }
.brand-name small { display: block; margin-top: 2px; font-size: 10px; font-weight: 450; letter-spacing: 1.8px; color: var(--muted); }
.brand > small { color: var(--muted); font-size: 12px; padding-left: 13px; border-left: 1px solid var(--line); }
.header-nav { display: flex; align-items: center; gap: 29px; margin-left: auto; font-size: 13px; }
.header-nav a { padding: 9px 0; color: var(--muted); }
.header-nav a:hover, .header-nav a[aria-current="page"] { color: var(--accent); }
.header-actions { display: flex; flex: 0 0 auto; align-items: center; gap: 13px; }
.search-trigger { display: inline-flex; align-items: center; gap: 12px; min-height: 35px; padding: 7px 11px; border: 1px solid var(--line); border-radius: 5px; background: var(--canvas); color: var(--muted); font-size: 12px; }
.search-trigger svg { width: 15px; height: 15px; }
.search-trigger kbd { margin-left: 18px; color: var(--faint); font: 11px var(--sans); }
.theme-toggle, .menu-toggle { display: inline-grid; place-items: center; width: 34px; height: 36px; padding: 7px; background: transparent; border-radius: 5px; color: var(--muted); font-size: 20px; }
.theme-toggle svg, .menu-toggle svg { width: 20px; height: 20px; }
.theme-toggle:hover, .menu-toggle:hover { color: var(--accent); background: var(--accent-soft); }
.menu-toggle { display: none; }

.home-main { max-width: 1180px; margin: 0 auto; padding: 0 36px; }
.hero { display: grid; grid-template-columns: 1.25fr .9fr; align-items: center; gap: 80px; min-height: 559px; padding: 71px 0 78px; }
.hero-copy { max-width: 590px; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; margin: 0 0 20px; color: var(--green); font-size: 12px; font-weight: 500; }
.eyebrow::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--green); }
.hero h1 { margin: 0 0 23px; font: 600 clamp(34px, 3.7vw, 49px)/1.4 var(--serif); letter-spacing: -1.2px; }
.hero h1 span { display: block; }
.hero-description { max-width: 460px; margin: 0; color: var(--muted); font-size: 15px; line-height: 1.95; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 31px; }
.primary-button, .secondary-button { display: inline-flex; justify-content: center; align-items: center; gap: 12px; min-height: 45px; padding: 12px 22px; border: 1px solid var(--line); border-radius: 4px; font-size: 13px; font-weight: 500; }
.primary-button { border-color: #3447b0; color: #fff; background: #3447b0; }
.primary-button:hover { background: #28388f; border-color: #28388f; }
.secondary-button { background: var(--paper); }
.secondary-button:hover { border-color: var(--accent); color: var(--accent); }
.primary-button svg, .secondary-button svg { width: 16px; height: 16px; }
.book-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 22px; margin-top: 27px; color: var(--faint); font-size: 11px; line-height: 1.7; }
.book-meta span { display: inline-flex; align-items: center; gap: 6px; }
.book-meta svg { width: 13px; height: 13px; }
.book-art { position: relative; justify-self: center; width: 271px; height: 356px; margin: 7px 0 0; transform: rotate(-7deg); isolation: isolate; }
.book-art::before { content: ""; position: absolute; z-index: -2; inset: -12px -21px -18px 4px; border: 1px solid var(--line); background: var(--canvas); transform: rotate(12deg); border-radius: 2px 7px 7px 2px; }
.book-art::after { content: ""; position: absolute; z-index: -1; top: 10px; right: -7px; bottom: -6px; left: 15px; background: repeating-linear-gradient(to bottom, #fff 0 2px, #e2e6ed 2px 3px); border: 1px solid #d4daE6; border-radius: 0 5px 5px 0; box-shadow: 15px 21px 40px -21px #20294355; }
.book-cover { position: relative; display: flex; flex-direction: column; height: 100%; padding: 30px 31px 26px; overflow: hidden; border-radius: 2px 5px 5px 2px; background: #3447b0; color: #fff; box-shadow: inset 7px 0 9px -7px #17255e, inset 10px 0 0 #ffffff0b; }
.book-spine { position: absolute; z-index: 2; inset: 0 auto 0 0; width: 10px; background: #1b2d8130; border-right: 1px solid #ffffff14; border-radius: 2px 0 0 2px; font-size: 0; }
.book-edition { font-size: 10px; letter-spacing: 1px; opacity: .7; }
.book-title { position: relative; z-index: 2; margin: 26px 0 0; font: 500 31px/1.38 var(--serif); letter-spacing: -.5px; }
.book-title small { display: block; margin-top: 13px; font: 11px/1.6 var(--sans); letter-spacing: .3px; opacity: .7; }
.book-line { position: relative; flex: 1; min-height: 88px; margin: 10px 0 15px; }
.book-line::before, .book-line::after { content: ""; position: absolute; width: 102px; height: 65px; border: 1px solid #acb8ff65; transform: skewY(-22deg); }
.book-line::before { top: 13px; left: 18px; }
.book-line::after { top: 35px; left: 69px; border-color: #cfdbff91; }
.book-author { position: relative; margin-top: auto; font-size: 9px; letter-spacing: .7px; opacity: .76; }
.book-author span { display: block; margin-top: 7px; font-size: 8px; opacity: .72; }
.reading-resume { display: flex; flex-wrap: wrap; align-items: center; gap: 9px 20px; margin-bottom: 37px; padding: 17px 22px; border-left: 3px solid var(--accent); background: var(--accent-soft); font-size: 13px; line-height: 1.7; }
.reading-resume > a { margin-left: auto; color: var(--accent); }
.reading-resume small, .reading-resume span { color: var(--muted); }
.catalog { padding: 36px 0 83px; border-top: 1px solid var(--line); scroll-margin-top: 90px; }
.section-heading { display: flex; justify-content: space-between; align-items: baseline; gap: 18px; margin: 0 0 33px; }
.section-heading h2 { margin: 0; font: 600 24px/1.5 var(--serif); }
.section-heading p { margin: 0; color: var(--faint); font-size: 12px; line-height: 1.7; }
.section-heading .eyebrow { display: block; margin-bottom: 7px; color: var(--green); font-size: 10px; }
.section-heading .eyebrow::before { display: none; }
.catalog-layout { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 54px; }
.learning-path { align-self: start; padding: 23px 25px 25px; border-top: 2px solid var(--green); background: var(--canvas); }
.learning-path h3 { margin: 0 0 14px; font: 600 16px/1.5 var(--serif); }
.learning-path p { margin: 0 0 18px; color: var(--muted); font-size: 12px; line-height: 1.95; }
.learning-path ol { margin: 21px 0 0; padding: 0; list-style: none; }
.learning-path li { position: relative; margin: 0; padding: 0 0 24px 22px; border-left: 1px solid var(--line); color: var(--muted); font-size: 12px; line-height: 1.7; }
.learning-path li:last-child { padding-bottom: 0; border-left-color: transparent; }
.learning-path li::before { position: absolute; content: ""; top: 5px; left: -4px; width: 7px; height: 7px; border: 2px solid var(--green); border-radius: 50%; background: var(--canvas); }
.learning-path li strong { display: block; margin-bottom: 4px; color: var(--ink); font-weight: 500; }
.learning-path a { color: var(--green); }
.learning-path > a { display: inline-block; margin-top: 22px; font-size: 11px; }
.learning-path li p { margin: 0; font-size: inherit; }
.chapter-group { margin: 0 0 29px; }
.chapter-group:last-child { margin-bottom: 0; }
.chapter-group h3 { margin: 0 0 8px; padding: 0 0 13px; color: var(--muted); font-size: 11px; font-weight: 450; }
.chapter-list { border-top: 1px solid var(--line); }
.chapter-row { display: flex; align-items: center; gap: 21px; min-height: 85px; padding: 17px 8px 17px 0; border-bottom: 1px solid var(--line); }
.chapter-number { flex: 0 0 31px; color: var(--faint); font: 400 18px/1.3 var(--serif); font-variant-numeric: tabular-nums; }
.chapter-info { min-width: 0; }
.chapter-info strong { display: block; color: var(--ink); font-size: 15px; line-height: 1.55; font-weight: 500; overflow-wrap: anywhere; }
.chapter-info small { display: block; margin-top: 5px; color: var(--faint); font-size: 11px; line-height: 1.6; overflow-wrap: anywhere; }
.chapter-arrow { margin-left: auto; padding-left: 15px; color: var(--faint); font-size: 17px; }
.chapter-row:hover .chapter-info strong, .chapter-row:hover .chapter-number, .chapter-row:hover .chapter-arrow { color: var(--accent); }
.chapter-row:hover { background: var(--canvas); }
.site-footer { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px 30px; padding: 29px max(32px, calc((100vw - 1108px) / 2)); border-top: 1px solid var(--line); color: var(--faint); font-size: 11px; line-height: 1.9; }
.site-footer p { margin: 0; }
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--accent); }
.site-footer .footer-brand { display: inline-block; margin-bottom: 5px; color: var(--ink); font-size: 12px; font-weight: 500; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 20px; }

/* The reading surface keeps the chapter, its place, and its outline together. */
.scroll-progress { position: fixed; z-index: 50; top: 0; left: 0; height: 2px; width: 0; background: var(--accent); }
.reading-layout { display: grid; grid-template-columns: 220px minmax(0, 760px) 175px; gap: 44px; max-width: 1480px; min-height: calc(100vh - 84px); margin: 0 auto; padding: 0 32px; }
.sidebar { position: sticky; top: 84px; align-self: start; height: calc(100vh - 84px); padding: 37px 21px 40px 0; border-right: 1px solid var(--line); overflow-y: auto; scrollbar-width: thin; scrollbar-color: var(--line) transparent; }
.sidebar-heading { display: block; margin: 0 0 23px; color: var(--muted); font-size: 12px; font-weight: 500; }
.sidebar-heading a:hover { color: var(--accent); }
.sidebar-nav { display: flex; flex-direction: column; gap: 5px; }
.sidebar-nav h3, .sidebar-nav .nav-group { margin: 24px 0 8px; padding: 0 11px; font-size: 10px; font-weight: 450; color: var(--faint); }
.sidebar-nav h3:first-child { margin-top: 0; }
.sidebar-nav a { display: flex; gap: 10px; padding: 10px 11px; border-radius: 4px; color: var(--muted); font-size: 12px; line-height: 1.7; overflow-wrap: anywhere; }
.sidebar-nav a > span:first-child { flex: 0 0 18px; color: var(--faint); font-variant-numeric: tabular-nums; }
.sidebar-nav a:hover { color: var(--accent); background: var(--canvas); }
.sidebar-nav a.active { color: var(--accent); background: var(--accent-soft); font-weight: 500; }
.sidebar-nav a.active > span:first-child { color: var(--accent); }
.sidebar-source { display: block; margin: 28px 11px 0; padding-top: 19px; border-top: 1px solid var(--line); color: var(--faint); font-size: 10px; }
.sidebar-source:hover { color: var(--accent); }
.reader { min-width: 0; padding: 42px 0 68px; }
.reader-header { padding-bottom: 29px; margin-bottom: 34px; border-bottom: 1px solid var(--line); }
.breadcrumb { display: flex; flex-wrap: wrap; align-items: center; gap: 9px; margin-bottom: 23px; color: var(--faint); font-size: 11px; line-height: 1.7; }
.breadcrumb a:hover { color: var(--accent); }
.reader-header h1 { margin: 0; font: 600 clamp(25px, 2.4vw, 35px)/1.55 var(--serif); letter-spacing: -.4px; overflow-wrap: anywhere; }
.reader-subtitle { margin: 12px 0 0; color: var(--muted); font-size: 14px; line-height: 1.8; }
.reader-tools { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; margin-top: 24px; color: var(--faint); font-size: 11px; }
.language-toggle { display: inline-flex; align-items: center; gap: 8px; padding: 7px 11px; border: 1px solid var(--line); border-radius: 4px; background: var(--canvas); color: var(--muted); font-size: 11px; }
.language-toggle:hover, .language-toggle[aria-pressed="true"] { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.prose { font-size: 15px; line-height: 1.95; overflow-wrap: anywhere; }
.prose > :first-child { margin-top: 0; }
.prose p { margin: 0 0 1.4em; }
.prose h1, .prose h2, .prose h3, .prose h4 { color: var(--ink); font-family: var(--serif); font-weight: 600; line-height: 1.6; scroll-margin-top: 111px; }
.prose h1 { margin: 1.9em 0 .8em; font-size: 30px; }
.prose h2 { margin: 2.4em 0 1em; padding-top: 4px; font-size: 24px; }
.prose h3 { margin: 2em 0 .8em; font-size: 20px; }
.prose h4 { margin: 1.8em 0 .8em; font-size: 17px; }
.prose a { color: var(--accent); text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--accent) 30%, transparent); text-underline-offset: 4px; }
.prose a:hover { text-decoration-color: var(--accent); }
.prose strong { font-weight: 600; }
.prose ul, .prose ol { padding-left: 1.7em; margin: .8em 0 1.6em; }
.prose li { padding-left: .2em; margin: .55em 0; }
.prose li > p { margin-bottom: .5em; }
.prose li::marker { color: var(--muted); }
.prose blockquote { margin: 25px 0; padding: 17px 22px; border-left: 3px solid var(--green); background: var(--canvas); color: var(--muted); font-size: 14px; }
.prose blockquote > :last-child { margin-bottom: 0; }
.prose hr { margin: 38px 0; border: 0; border-top: 1px solid var(--line); }
.prose code { padding: 2px 5px; border-radius: 3px; background: var(--code); font: .86em/1.6 var(--mono); }
.prose pre { position: relative; max-width: 100%; margin: 25px 0; padding: 42px 23px 20px; overflow-x: auto; border: 1px solid var(--line); border-radius: 4px; background: var(--code); font: 12px/1.85 var(--mono); tab-size: 4; overflow-wrap: normal; white-space: pre; }
.prose pre code { padding: 0; border: 0; background: transparent; font: inherit; white-space: pre; }
.copy-code { position: absolute; top: 9px; right: 10px; padding: 3px 8px; border: 1px solid var(--line); border-radius: 3px; background: var(--paper); color: var(--muted); font: 10px/1.6 var(--sans); }
.copy-code:hover { color: var(--accent); border-color: var(--accent); }
body[data-theme="dark"] .prose .hljs { color: #d7e0f3; background: transparent; }
body[data-theme="dark"] .prose .hljs-keyword, body[data-theme="dark"] .prose .hljs-selector-tag, body[data-theme="dark"] .prose .hljs-template-tag, body[data-theme="dark"] .prose .hljs-type { color: #c4adff; }
body[data-theme="dark"] .prose .hljs-title, body[data-theme="dark"] .prose .hljs-section, body[data-theme="dark"] .prose .hljs-built_in { color: #91beff; }
body[data-theme="dark"] .prose .hljs-string, body[data-theme="dark"] .prose .hljs-regexp, body[data-theme="dark"] .prose .hljs-addition { color: #9ad2bc; }
body[data-theme="dark"] .prose .hljs-comment, body[data-theme="dark"] .prose .hljs-quote { color: #94a1ba; }
body[data-theme="dark"] .prose .hljs-number, body[data-theme="dark"] .prose .hljs-literal, body[data-theme="dark"] .prose .hljs-attr, body[data-theme="dark"] .prose .hljs-attribute, body[data-theme="dark"] .prose .hljs-variable { color: #e6be87; }
body[data-theme="dark"] .prose .hljs-symbol, body[data-theme="dark"] .prose .hljs-deletion, body[data-theme="dark"] .prose .hljs-meta { color: #f2a7b3; }
.prose table { display: block; width: 100%; max-width: 100%; margin: 26px 0; overflow-x: auto; border-collapse: collapse; font-size: 12px; line-height: 1.8; }
.prose th, .prose td { min-width: 95px; padding: 12px 15px; border: 1px solid var(--line); vertical-align: top; text-align: left; }
.prose th { background: var(--canvas); font-weight: 550; }
.prose tr:nth-child(even) td { background: color-mix(in srgb, var(--canvas) 55%, var(--paper)); }
.prose img { display: block; max-height: 670px; margin: 29px auto; object-fit: contain; cursor: zoom-in; border-radius: 3px; }
.prose figure { max-width: 100%; margin: 28px 0; }
.prose figure img { margin-bottom: 13px; }
.prose figcaption { color: var(--muted); text-align: center; font-size: 12px; }
.prose .english { color: var(--muted); font-size: .94em; line-height: 1.85; }
body.hide-english .prose .english, body[data-language="zh"] .prose .english { display: none; }
.prose .footnotes { margin-top: 45px; font-size: 12px; }
.prose sup { line-height: 0; }
.chapter-pagination { display: grid; grid-template-columns: 1fr 1fr; gap: 25px; margin-top: 65px; padding-top: 26px; border-top: 1px solid var(--line); }
.chapter-pagination a { display: flex; flex-direction: column; gap: 9px; min-width: 0; padding: 5px 0; }
.chapter-pagination a:last-child { text-align: right; }
.chapter-pagination a:only-child { grid-column: 1 / -1; }
.chapter-pagination small { color: var(--faint); font-size: 11px; }
.chapter-pagination strong { font-size: 13px; font-weight: 500; line-height: 1.6; overflow-wrap: anywhere; }
.chapter-pagination a:hover strong { color: var(--accent); }
.toc { position: sticky; top: 84px; align-self: start; max-height: calc(100vh - 84px); padding: 41px 0 35px; overflow-y: auto; scrollbar-width: thin; scrollbar-color: var(--line) transparent; }
.toc-heading { margin: 0 0 17px; font-size: 11px; font-weight: 500; color: var(--ink); }
.toc nav { display: flex; flex-direction: column; gap: 11px; padding-left: 14px; border-left: 1px solid var(--line); }
.toc nav a { position: relative; color: var(--muted); font-size: 11px; line-height: 1.7; overflow-wrap: anywhere; }
.toc nav a.depth-3 { padding-left: 10px; font-size: 10px; color: var(--faint); }
.toc nav a:hover, .toc nav a.active { color: var(--accent); }
.toc nav a.active::before { content: ""; position: absolute; top: 2px; bottom: 2px; left: -15px; width: 2px; background: var(--accent); }
.reading-progress { margin-top: 31px; padding-top: 21px; border-top: 1px solid var(--line); }
.reading-progress progress { display: block; width: 100%; height: 3px; margin: 12px 0 0; overflow: hidden; border: 0; border-radius: 2px; appearance: none; background: var(--line); color: var(--accent); }
.reading-progress progress::-webkit-progress-bar { background: var(--line); }
.reading-progress progress::-webkit-progress-value { background: var(--accent); }
.reading-progress progress::-moz-progress-bar { background: var(--accent); }
.progress-label { display: flex; justify-content: space-between; color: var(--faint); font-size: 10px; line-height: 1.6; }
.menu-backdrop { display: none; }
body[data-page="about"] .reader { width: min(100% - 48px, 740px); margin: 0 auto; padding: 65px 0 90px; }
.about-main { width: min(100% - 64px, 760px); min-height: calc(100vh - 252px); margin: 0 auto; padding: 59px 0 80px; }
.about-main > h1 { margin: 0 0 35px; font: 600 33px/1.6 var(--serif); }
.about-main > p { color: var(--muted); font-size: 14px; line-height: 1.9; }
.about-main > .primary-button { margin-top: 17px; }

/* Search remains usable with a keyboard, on a narrow screen, and in both themes. */
.search-dialog { width: min(640px, calc(100vw - 32px)); max-height: min(680px, calc(100dvh - 100px)); margin: 95px auto auto; padding: 0; overflow: hidden; border: 1px solid var(--line); border-radius: 10px; background: var(--paper); color: var(--ink); box-shadow: 0 25px 100px #141e3c30; }
.search-dialog[open] { display: flex; flex-direction: column; }
.search-dialog::backdrop, .image-dialog::backdrop { background: #15213d70; backdrop-filter: blur(4px); }
.search-head { display: flex; align-items: center; gap: 15px; padding: 17px 21px; border-bottom: 1px solid var(--line); }
.search-head > svg { width: 20px; height: 20px; color: var(--faint); }
.search-head input { min-width: 0; width: 100%; padding: 6px 0; border: 0; outline: 0; background: transparent; color: var(--ink); font-size: 16px; }
.search-head input::placeholder { color: var(--faint); }
.search-head input:focus-visible { outline: 0; }
.close-search { flex: 0 0 auto; min-width: 31px; min-height: 31px; padding: 5px; border: 1px solid var(--line); border-radius: 4px; background: var(--canvas); color: var(--muted); font-size: 11px; }
.search-status { padding: 18px 22px 10px; color: var(--muted); font-size: 12px; line-height: 1.7; }
.search-status:empty { display: none; }
#search-results { overflow-y: auto; overscroll-behavior: contain; padding: 5px 10px 13px; }
.search-result { display: block; padding: 15px 13px; border-radius: 5px; }
.search-result + .search-result { border-top: 1px solid var(--line); }
.search-result:hover, .search-result:focus-visible { background: var(--accent-soft); }
.search-result strong { display: block; font-size: 14px; font-weight: 500; line-height: 1.7; overflow-wrap: anywhere; }
.search-result small { display: block; margin-top: 3px; color: var(--faint); font-size: 11px; line-height: 1.7; }
.search-result span { display: block; margin-top: 6px; color: var(--muted); font-size: 12px; line-height: 1.8; overflow-wrap: anywhere; }
.search-result mark { padding: 1px 2px; border-radius: 2px; background: var(--accent-soft); color: var(--accent); }
.search-hint { margin: 0; padding: 12px 22px; border-top: 1px solid var(--line); background: var(--canvas); color: var(--faint); font-size: 10px; line-height: 1.7; }
.search-hint kbd { font-family: var(--sans); }
.image-dialog { max-width: calc(100vw - 48px); max-height: calc(100dvh - 48px); padding: 22px; border: 0; border-radius: 5px; background: var(--paper); color: var(--ink); }
.image-dialog img { display: block; max-width: min(1400px, calc(100vw - 92px)); max-height: calc(100dvh - 110px); margin: 0 auto; object-fit: contain; }
.image-dialog button { position: absolute; top: 7px; right: 7px; display: grid; place-items: center; min-width: 32px; min-height: 32px; padding: 6px 10px; border: 1px solid var(--line); border-radius: 4px; background: var(--paper); color: var(--ink); font-size: 11px; }

@media (min-width: 1600px) {
  .reading-layout { grid-template-columns: 232px minmax(0, 800px) 184px; gap: 51px; max-width: 1530px; }
}
@media (max-width: 1170px) {
  .site-header { gap: 22px; }
  .reading-layout { grid-template-columns: 195px minmax(0, 1fr); gap: 34px; padding: 0 28px; }
  .toc { display: none; }
  .hero { gap: 45px; }
  .catalog-layout { gap: 36px; grid-template-columns: 195px minmax(0, 1fr); }
}
@media (max-width: 900px) {
  .site-header { padding: 0 25px; gap: 17px; }
  .header-nav { gap: 19px; }
  .search-trigger kbd { display: none; }
  .home-main { padding: 0 32px; }
  .hero { grid-template-columns: 1.2fr .85fr; gap: 27px; min-height: 490px; padding: 58px 0 65px; }
  .hero h1 { font-size: 36px; }
  .hero-description { font-size: 13px; }
  .book-art { width: 224px; height: 304px; }
  .book-cover { padding: 25px 25px 22px; }
  .book-title { font-size: 26px; margin-top: 21px; }
  .book-line::before, .book-line::after { width: 78px; height: 51px; }
  .book-line::after { left: 56px; }
  .catalog-layout { grid-template-columns: 170px minmax(0, 1fr); gap: 28px; }
  .learning-path { padding: 21px 18px; }
  .reading-layout { grid-template-columns: 172px minmax(0, 1fr); gap: 26px; padding: 0 23px; }
  .sidebar { padding-right: 13px; }
  .prose { font-size: 14px; }
  .sidebar-nav a { padding: 9px 7px; font-size: 11px; }
}
@media (max-width: 760px) {
  :root { scroll-padding-top: 86px; }
  .site-header { min-height: 68px; gap: 13px; padding: 0 22px; }
  .brand { gap: 9px; }
  .brand-icon { width: 31px; height: 31px; font-size: 19px; }
  .brand-name { font-size: 19px; }
  .brand-name small { font-size: 9px; letter-spacing: 1.25px; }
  .brand > small { display: none; }
  .header-nav { margin-left: auto; gap: 17px; font-size: 12px; }
  .header-actions { gap: 7px; }
  .search-trigger { min-height: 33px; padding: 8px; border-color: transparent; background: transparent; gap: 0; }
  .search-trigger span, .search-trigger kbd { display: none; }
  .theme-toggle { width: 30px; height: 33px; }
  body[data-page="chapter"] .header-nav { display: none; }
  body[data-page="chapter"] .header-actions { margin-left: auto; }
  body[data-page="chapter"] .search-trigger { margin-left: auto; }
  body[data-page="chapter"] .menu-toggle { display: inline-grid; }
  .home-main { padding: 0 25px; }
  .hero { min-height: auto; gap: 20px; padding: 55px 0 56px; }
  .hero h1 { font-size: 31px; letter-spacing: -.7px; }
  .eyebrow { font-size: 10px; margin-bottom: 17px; }
  .hero-description { font-size: 12px; line-height: 1.9; }
  .hero-actions { gap: 10px; margin-top: 24px; }
  .primary-button, .secondary-button { padding: 10px 16px; min-height: 41px; font-size: 12px; }
  .book-meta { font-size: 10px; margin-top: 23px; gap: 6px 14px; }
  .book-art { width: 183px; height: 255px; }
  .book-cover { padding: 23px 22px 19px; }
  .book-edition { font-size: 8px; letter-spacing: .5px; }
  .book-title { font-size: 23px; margin-top: 18px; }
  .book-title small { font-size: 9px; margin-top: 10px; }
  .book-author { font-size: 7px; letter-spacing: .2px; }
  .book-line { min-height: 65px; margin: 2px 0 7px; }
  .book-line::before, .book-line::after { width: 63px; height: 43px; }
  .book-line::before { left: 5px; top: 10px; }
  .book-line::after { left: 40px; top: 26px; }
  .catalog { padding: 29px 0 49px; }
  .section-heading { align-items: flex-start; gap: 14px; margin-bottom: 26px; }
  .section-heading h2 { font-size: 22px; }
  .section-heading p { max-width: 180px; font-size: 10px; padding-top: 6px; text-align: right; }
  .section-heading .eyebrow { text-align: left; padding-top: 0; }
  .catalog-layout { display: block; }
  .learning-path { margin-bottom: 31px; padding: 18px 20px; }
  .learning-path h3 { font-size: 14px; margin-bottom: 8px; }
  .learning-path p { margin-bottom: 0; }
  .learning-path ol { display: flex; gap: 20px; margin-top: 20px; }
  .learning-path li { flex: 1; padding: 0 0 0 13px; border-left: 0; font-size: 10px; }
  .learning-path li::before { left: 0; }
  .learning-path li strong { font-size: 11px; }
  .chapter-row { min-height: 82px; gap: 16px; }
  .chapter-info strong { font-size: 14px; }
  .chapter-info small { font-size: 10px; }
  .reading-resume { padding: 14px 17px; font-size: 12px; }
  .reading-layout { display: block; min-height: calc(100vh - 68px); padding: 0 25px; }
  .reader { padding-top: 29px; padding-bottom: 45px; }
  .reader-header { padding-bottom: 24px; margin-bottom: 26px; }
  .reader-header h1 { font-size: 28px; }
  .breadcrumb { margin-bottom: 18px; }
  .reader-subtitle { font-size: 12px; }
  .reader-tools { margin-top: 19px; }
  .prose { font-size: 15px; line-height: 1.95; }
  .prose h2 { font-size: 22px; scroll-margin-top: 89px; }
  .prose h3 { font-size: 19px; scroll-margin-top: 89px; }
  .prose h4 { font-size: 16px; scroll-margin-top: 89px; }
  .prose pre { padding: 38px 16px 16px; font-size: 11px; }
  .prose blockquote { padding: 15px 17px; font-size: 13px; }
  .prose table { font-size: 11px; }
  .prose th, .prose td { padding: 10px 12px; }
  .chapter-pagination { gap: 18px; margin-top: 45px; }
  .chapter-pagination strong { font-size: 12px; }
  .sidebar { position: fixed; z-index: 45; top: 68px; bottom: 0; left: 0; width: min(310px, 85vw); height: calc(100dvh - 68px); padding: 28px 22px 40px; background: var(--paper); transform: translateX(-101%); visibility: hidden; transition: transform .2s ease, visibility .2s; }
  .sidebar-nav a { padding: 10px 12px; font-size: 13px; }
  .sidebar-nav h3, .sidebar-nav .nav-group { font-size: 11px; }
  body.menu-open { overflow: hidden; }
  body.menu-open .sidebar { transform: none; visibility: visible; }
  body.menu-open .menu-backdrop { display: block; position: fixed; z-index: 40; inset: 68px 0 0; width: 100%; height: calc(100dvh - 68px); padding: 0; background: #10193266; }
  .site-footer { padding: 24px 25px; font-size: 10px; }
  .search-dialog { margin-top: 80px; max-height: calc(100dvh - 100px); }
  .search-head { padding: 13px 16px; gap: 12px; }
  .search-head input { font-size: 16px; }
  .search-result { padding: 13px 10px; }
  .image-dialog { max-width: calc(100vw - 20px); padding: 18px 10px; }
  .image-dialog img { max-width: calc(100vw - 40px); }
  body[data-page="about"] .reader { width: calc(100% - 50px); padding-top: 38px; }
  .about-main { width: calc(100% - 50px); padding: 36px 0 55px; }
  .about-main > h1 { font-size: 27px; margin-bottom: 27px; }
}
@media (max-width: 520px) {
  .site-header { gap: 10px; padding: 0 18px; }
  .header-nav { gap: 15px; }
  .header-nav a:nth-child(n+3) { display: none; }
  .home-main { padding: 0 23px; }
  .hero { position: relative; grid-template-columns: minmax(0, 1fr); gap: 38px; padding: 41px 0 39px; }
  .hero-copy { position: relative; z-index: 1; }
  .hero h1 { max-width: 320px; font-size: 35px; line-height: 1.4; }
  .hero-description { max-width: 335px; font-size: 13px; }
  .hero-actions { margin-top: 25px; }
  .book-art { justify-self: center; width: 190px; height: 255px; margin: 3px 0 15px; }
  .book-title { font-size: 24px; }
  .book-meta { max-width: 330px; font-size: 10px; }
  .section-heading p { max-width: 160px; }
  .learning-path ol { gap: 15px; }
  .chapter-number { flex-basis: 25px; font-size: 17px; }
  .chapter-row { gap: 13px; }
  .chapter-arrow { padding-left: 5px; }
  .reading-layout { padding: 0 22px; }
  .reader-header h1 { font-size: 26px; }
  .reader-tools { gap: 10px; }
  .prose { font-size: 14px; }
  .site-footer { display: block; padding: 23px; }
  .site-footer > * + * { margin-top: 10px; }
}
@media (max-width: 380px) {
  .book-art { width: 175px; height: 235px; }
  .header-nav a:nth-child(n+2) { display: none; }
  .header-nav a { white-space: nowrap; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}
@media print {
  :root, body[data-theme="dark"] { color-scheme: light; --paper: #fff; --ink: #111; --muted: #444; --line: #ccc; --code: #f4f4f4; }
  .site-header, .sidebar, .toc, .site-footer, .reader-tools, .chapter-pagination, .scroll-progress, .menu-backdrop, .search-dialog, .copy-code { display: none !important; }
  .reading-layout { display: block; max-width: none; padding: 0; }
  .reader { padding: 0; }
  .reader-header { margin-bottom: 20px; }
  .prose { font-size: 10pt; }
  .prose pre { white-space: pre-wrap; overflow-wrap: anywhere; }
  .prose h2, .prose h3, .prose h4 { break-after: avoid; }
  .prose img, .prose tr { break-inside: avoid; }
  .prose a { color: inherit; }
}