/* assets/topic-lab.css */
:root {
  --paper: #f3ebd9;
  --paper-deep: #e6d9be;
  --ink: #1b201c;
  --muted: #6a6f65;
  --accent: #a3382a;
  --accent-2: #c9973f;
  --panel: rgba(255, 253, 246, 0.88);
  --line: rgba(60, 52, 38, 0.14);
  --line-soft: rgba(60, 52, 38, 0.08);
  --shadow: 0 2px 5px rgba(72, 57, 32, 0.05), 0 18px 44px rgba(72, 57, 32, 0.10);
  --serif: "Songti SC", "STSong", "SimSun", "Noto Serif SC", serif;
  --display: "Kaiti SC", "STKaiti", "KaiTi", "Noto Serif SC", serif;
  --sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, sans-serif;
  --r: 14px;
  --r-sm: 10px;
  --r-seal: 18px 18px 18px 5px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='260' height='260'%3E%3Cfilter id='p'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.78' numOctaves='4' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='260' height='260' filter='url(%23p)' opacity='0.045'/%3E%3C/svg%3E") repeat,
    radial-gradient(circle at 8% 2%, color-mix(in srgb, var(--accent-2) 13%, transparent), transparent 34rem),
    linear-gradient(135deg, rgba(255, 255, 255, .4), transparent 42%),
    var(--paper);
  background-attachment: fixed;
  font-family: var(--sans);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
img { display: block; max-width: 100%; }
::selection { color: #fff7ea; background: var(--accent); }
:where(a, button, input, select, textarea, [tabindex]):focus-visible { outline: 3px solid color-mix(in srgb, var(--accent) 45%, transparent); outline-offset: 3px; }
.wrap { width: min(1180px, calc(100% - 40px)); margin-inline: auto; }
.skip-link { position: fixed; top: -80px; left: 18px; z-index: 10000; padding: 10px 16px; color: white; background: var(--ink); border-radius: var(--r-sm); }
.skip-link:focus { top: 12px; }

.topic-hero { position: relative; overflow: hidden; min-height: 400px; color: #fff; background: var(--hero, #17251f); }
.topic-hero::before {
  content: ""; position: absolute; inset: 0; opacity: .22;
  background-image: linear-gradient(rgba(255, 255, 255, .07) 1px, transparent 1px), linear-gradient(90deg, rgba(255, 255, 255, .07) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: linear-gradient(to bottom, black, transparent 82%);
}
.topic-hero::after { content: ""; position: absolute; right: -8vw; top: -22vw; width: 56vw; height: 56vw; border: 1px solid rgba(255, 255, 255, .13); border-radius: 50%; box-shadow: 0 0 0 7vw rgba(255, 255, 255, .022), 0 0 0 14vw rgba(255, 255, 255, .018); }
.hero-inner { position: relative; z-index: 1; padding: 76px 0 68px; }
.hero-kicker, .section-kicker { display: flex; align-items: center; gap: 12px; margin: 0 0 14px; color: var(--accent-2); font-size: 12px; font-weight: 800; letter-spacing: .2em; text-transform: uppercase; }
.hero-kicker::before, .section-kicker::before { flex: 0 0 auto; width: 32px; height: 1px; content: ""; background: currentColor; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(258px, .72fr); gap: 60px; align-items: end; }
.topic-hero h1 { margin: 0; max-width: 780px; font-family: var(--display); font-size: clamp(48px, 6.6vw, 82px); line-height: 1.1; font-weight: 700; letter-spacing: .035em; }
.topic-hero h1 em { display: block; margin-top: 14px; color: var(--accent-2); font-size: .42em; font-style: normal; font-weight: 700; letter-spacing: .09em; }
.hero-intro { max-width: 700px; margin: 26px 0 0; color: rgba(255, 255, 255, .76); font-family: var(--serif); font-size: 17px; line-height: 1.95; letter-spacing: .03em; }
.hero-stats { display: grid; gap: 1px; overflow: hidden; border: 1px solid rgba(255, 255, 255, .16); border-radius: var(--r); background: rgba(255, 255, 255, .14); box-shadow: 0 18px 52px rgba(0, 0, 0, .22); backdrop-filter: blur(12px); }
.hero-stats div { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; padding: 19px 22px; background: rgba(9, 14, 12, .66); }
.hero-stats strong { color: var(--accent-2); font-family: var(--serif); font-size: 34px; font-weight: 600; line-height: 1; }
.hero-stats span { color: rgba(255, 255, 255, .68); font-size: 13px; letter-spacing: .04em; }

.course-nav { position: sticky; top: 0; z-index: 30; border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--paper) 88%, transparent); backdrop-filter: blur(16px); }
.nav-inner { display: flex; gap: 2px; overflow-x: auto; scrollbar-width: none; }
.nav-inner::-webkit-scrollbar { display: none; }
.nav-inner button { position: relative; flex: 0 0 auto; min-height: 60px; padding: 0 22px; color: var(--muted); border: 0; background: transparent; font-weight: 800; letter-spacing: .03em; transition: color .18s ease; }
.nav-inner button::after { position: absolute; right: 22px; bottom: 0; left: 22px; height: 3px; content: ""; background: var(--accent); border-radius: 3px 3px 0 0; opacity: 0; transition: opacity .18s ease; }
.nav-inner button:hover { color: var(--ink); }
.nav-inner button.on { color: var(--accent); }
.nav-inner button.on::after { opacity: 1; }

.tab-panel { padding: 74px 0 88px; }
.tab-panel[hidden] { display: none !important; }
.section-heading { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(280px, .7fr); gap: 54px; align-items: end; margin-bottom: 36px; }
.section-heading h2 { margin: 0; font-family: var(--display); font-size: clamp(32px, 4.6vw, 52px); font-weight: 700; line-height: 1.18; letter-spacing: .05em; }
.section-heading > p { margin: 0; color: var(--muted); font-family: var(--serif); line-height: 1.95; letter-spacing: .03em; }

.panel { border: 1px solid var(--line); border-radius: var(--r); background: var(--panel); box-shadow: var(--shadow); }
.card-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
.info-card { position: relative; overflow: hidden; padding: 25px; border: 1px solid var(--line); border-radius: var(--r-seal); background: rgba(255, 255, 255, .58); transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease; }
.info-card::before { position: absolute; inset: 0 auto 0 0; width: 3px; content: ""; background: var(--accent); opacity: 0; transition: opacity .2s ease; }
.info-card:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--accent) 38%, transparent); box-shadow: var(--shadow); }
.info-card:hover::before { opacity: 1; }
.info-card .card-index { color: var(--accent); font-size: 12px; font-weight: 900; letter-spacing: .14em; }
.info-card h3 { margin: 14px 0 9px; font-family: var(--display); font-size: 25px; font-weight: 700; line-height: 1.24; letter-spacing: .04em; }
.info-card p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.85; }

.control-bar { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin-bottom: 22px; padding: 17px; border: 1px solid var(--line); border-radius: var(--r); background: rgba(255, 255, 255, .55); box-shadow: 0 1px 2px rgba(72, 57, 32, .04); }
.control-bar input, .control-bar select, .field input, .field select { min-height: 46px; padding: 0 14px; color: var(--ink); border: 1px solid var(--line); border-radius: var(--r-sm); background: #fffdf8; outline: none; transition: border-color .18s ease, box-shadow .18s ease; }
.control-bar input:focus, .control-bar select:focus, .field input:focus, .field select:focus { border-color: color-mix(in srgb, var(--accent) 45%, transparent); box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 10%, transparent); }
.control-bar input { flex: 1 1 240px; }
.field { display: grid; gap: 7px; }
.field label { color: var(--muted); font-size: 12px; font-weight: 800; letter-spacing: .1em; }
.primary-button, .secondary-button { min-height: 46px; padding: 0 20px; border: 1px solid var(--accent); border-radius: var(--r-sm); font-weight: 800; letter-spacing: .04em; transition: transform .16s ease, box-shadow .16s ease, background-color .16s ease; }
.primary-button { color: white; background: var(--accent); box-shadow: 0 4px 14px color-mix(in srgb, var(--accent) 26%, transparent); }
.primary-button:hover { transform: translateY(-2px); box-shadow: 0 8px 20px color-mix(in srgb, var(--accent) 32%, transparent); }
.secondary-button { color: var(--accent); background: transparent; }
.secondary-button:hover { background: color-mix(in srgb, var(--accent) 8%, transparent); }
.source-note { display: flex; gap: 14px; align-items: flex-start; margin-top: 36px; padding: 18px 22px; color: var(--muted); border-left: 3px solid var(--accent-2); border-radius: 0 var(--r-sm) var(--r-sm) 0; background: rgba(255, 255, 255, .5); font-size: 13px; line-height: 1.85; }
.source-note strong { flex: 0 0 auto; color: var(--ink); }

.quiz-shell { max-width: 820px; margin: 0 auto; }
.quiz-status { margin-bottom: 16px; }
.quiz-status > div:first-child { display: flex; justify-content: space-between; margin-bottom: 10px; color: var(--muted); font-size: 13px; font-weight: 800; }
.progress-track { height: 5px; overflow: hidden; background: var(--paper-deep); border-radius: 999px; }
.progress-track span { display: block; width: 0; height: 100%; background: linear-gradient(90deg, var(--accent), color-mix(in srgb, var(--accent) 65%, var(--accent-2))); border-radius: 999px; transition: width .25s ease; }
.quiz-card, .quiz-finish { padding: clamp(26px, 5vw, 50px); border: 1px solid var(--line); border-radius: var(--r); background: var(--panel); box-shadow: var(--shadow); }
.quiz-level { margin: 0 0 12px; color: var(--accent); font-size: 12px; font-weight: 900; letter-spacing: .16em; }
.quiz-card h3, .quiz-finish h3 { margin: 0 0 28px; font-family: var(--display); font-size: clamp(26px, 3.6vw, 36px); font-weight: 700; line-height: 1.45; letter-spacing: .04em; }
.quiz-options { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.quiz-options button { min-height: 58px; padding: 13px 18px; text-align: left; color: var(--ink); border: 1px solid var(--line); border-radius: var(--r-sm); background: rgba(255, 255, 255, .7); font-weight: 700; transition: border-color .16s ease, background-color .16s ease, transform .16s ease; }
.quiz-options button:hover:not(:disabled) { border-color: var(--accent); background: #fffdf8; transform: translateY(-1px); }
.quiz-options button.correct { color: #1a5636; border-color: #3c8d61; background: #e8f5ec; }
.quiz-options button.wrong { color: #882f27; border-color: #b74c40; background: #f8e9e6; }
.quiz-feedback { display: grid; gap: 4px; margin-top: 18px; padding: 16px 20px; border-left: 3px solid var(--accent); border-radius: 0 var(--r-sm) var(--r-sm) 0; background: rgba(255, 255, 255, .6); }
.quiz-feedback strong { color: var(--accent); }
.quiz-feedback span { color: var(--muted); line-height: 1.85; }
.quiz-card [data-quiz-next], .quiz-finish button { margin-top: 20px; min-height: 48px; padding: 0 24px; color: white; border: 0; border-radius: var(--r-sm); background: var(--accent); box-shadow: 0 4px 14px color-mix(in srgb, var(--accent) 26%, transparent); font-weight: 800; letter-spacing: .04em; }
.quiz-finish { text-align: center; }
.quiz-finish p { color: var(--muted); }
.page-footer { display: flex; justify-content: space-between; gap: 24px; padding: 34px 0 86px; color: var(--muted); border-top: 1px solid var(--line); font-family: var(--serif); font-size: 13px; letter-spacing: .03em; }
.noscript { margin: 0; padding: 14px; color: white; text-align: center; background: #8d2f24; }

@media (max-width: 820px) {
  .hero-grid, .section-heading { grid-template-columns: 1fr; gap: 30px; }
  .hero-stats { grid-template-columns: repeat(3, 1fr); }
  .hero-stats div { display: grid; gap: 6px; justify-content: start; }
  .card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 560px) {
  .wrap { width: min(100% - 26px, 1180px); }
  .hero-inner { padding: 58px 0 48px; }
  .topic-hero { min-height: 0; }
  .topic-hero h1 { font-size: 44px; }
  .hero-stats { grid-template-columns: 1fr; }
  .hero-stats div { display: flex; }
  .nav-inner button { min-height: 54px; padding: 0 15px; font-size: 13px; }
  .nav-inner button::after { right: 15px; left: 15px; }
  .tab-panel { padding: 50px 0 66px; }
  .card-grid, .quiz-options { grid-template-columns: 1fr; }
  .page-footer { display: grid; padding-bottom: 78px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}

/* solar-system/style.css */
:root { --paper: #f3ebd9; --paper-deep: #e6d9be; --ink: #1b201c; --muted: #6a6f65; --accent: #1d5f89; --accent-2: #d3a14d; --panel: rgba(255,253,246,.9); --hero: #07111b; }
.topic-hero { background: radial-gradient(circle at 78% 34%, rgba(70,135,180,.28), transparent 24rem), radial-gradient(circle at 12% 12%, rgba(242,184,91,.18), transparent 18rem), #07111b; }
.planet-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 15px; }
.planet-card { overflow: hidden; padding: 0; color: var(--ink); text-align: left; border: 1px solid var(--line); background: rgba(255,255,255,.7); }
.planet-card.active { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(29,95,137,.15); }
.planet-card img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; background: #07111b; }
.planet-card div { padding: 16px; }
.planet-card span { color: var(--accent); font-size: 11px; font-weight: 900; letter-spacing: .12em; }
.planet-card strong { display: block; margin-top: 4px; font-family: var(--serif); font-size: 24px; }
.planet-detail { display: grid; grid-template-columns: 1.2fr repeat(4, 1fr); gap: 1px; margin-top: 18px; padding: 0; background: var(--line); }
.planet-detail > div { padding: 24px; background: rgba(253,254,255,.94); }
.planet-detail h3 { margin: 0 0 8px; font-family: var(--serif); font-size: 29px; }
.planet-detail p { margin: 0; color: var(--muted); font-size: 13px; }
.planet-detail small { display: block; color: var(--muted); font-size: 11px; }
.planet-detail strong { display: block; margin-top: 5px; font-size: 20px; }
.scale-compare { padding: 28px; }
.scale-controls { display: flex; justify-content: center; gap: 20px; align-items: end; }
.disk-stage { display: grid; grid-template-columns: 1fr 230px 1fr; gap: 24px; min-height: 390px; align-items: center; margin-top: 24px; padding: 24px; color: white; background: radial-gradient(circle, #1a3448, #07111b 70%); }
.disk-item { display: grid; justify-items: center; gap: 7px; }
.planet-disk { width: var(--disk-size, 120px); height: var(--disk-size, 120px); max-width: 240px; max-height: 240px; min-width: 16px; min-height: 16px; border-radius: 50%; background: var(--disk-color, #aaa); box-shadow: inset -18px -12px 30px rgba(0,0,0,.44), 0 0 36px color-mix(in srgb, var(--disk-color) 35%, transparent); transition: width .25s ease, height .25s ease; }
.disk-item strong { font-family: var(--serif); font-size: 25px; }
.disk-item span, .ratio-readout span { color: rgba(255,255,255,.62); font-size: 12px; }
.ratio-readout { text-align: center; }
.ratio-readout small { display: block; color: var(--accent-2); font-weight: 800; }
.ratio-readout strong { display: block; margin: 6px 0; font-family: var(--serif); font-size: 36px; }
.distance-panel { margin-top: 22px; padding: 28px; }
.distance-heading { display: flex; justify-content: space-between; gap: 30px; }
.distance-heading h3 { margin: 0; font-family: var(--serif); font-size: 27px; }
.distance-heading p { max-width: 520px; margin: 0; color: var(--muted); }
.distance-axis { position: relative; height: 210px; margin: 32px 10px 0; border-bottom: 2px solid var(--ink); }
.orbit-mark { position: absolute; bottom: -8px; transform: translateX(-50%); text-align: center; }
.orbit-mark::before { content: ""; display: block; width: 1px; height: var(--mark-height); margin: auto; background: color-mix(in srgb, var(--accent) 38%, transparent); }
.orbit-mark i { display: block; width: 16px; height: 16px; margin: -8px auto 8px; border: 3px solid white; border-radius: 50%; background: var(--planet-color); box-shadow: 0 0 0 1px var(--line); }
.orbit-mark strong { display: block; font-size: 12px; white-space: nowrap; }
.orbit-mark span { color: var(--muted); font-size: 10px; }
.au-note { display: flex; justify-content: space-between; gap: 26px; margin-top: 32px; padding-top: 18px; border-top: 1px solid var(--line); }
.au-note span { color: var(--muted); }
.dwarf-grid { display: grid; grid-template-columns: repeat(5, minmax(0,1fr)); gap: 14px; }
.dwarf-card { min-height: 260px; padding: 22px; color: white; background: linear-gradient(150deg, color-mix(in srgb, var(--dwarf) 72%, #111), #101922); }
.dwarf-card span { color: var(--accent-2); font-size: 11px; font-weight: 900; }
.dwarf-card h3 { margin: 20px 0 8px; font-family: var(--serif); font-size: 29px; }
.dwarf-card p { color: rgba(255,255,255,.7); font-size: 13px; }
.dwarf-card dl { margin: 20px 0 0; }
.dwarf-card div { display: flex; justify-content: space-between; gap: 10px; padding: 7px 0; border-top: 1px solid rgba(255,255,255,.14); font-size: 11px; }
.dwarf-card dd { margin: 0; font-weight: 800; }
.definition-strip { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 20px; border: 1px solid var(--line); background: rgba(255,255,255,.55); }
.definition-strip > div { display: flex; gap: 14px; padding: 22px; border-right: 1px solid var(--line); }
.definition-strip > div:last-child { border-right: 0; }
.definition-strip span { color: var(--accent); font-size: 22px; font-weight: 900; }
.definition-strip p { margin: 0; }
.definition-strip strong, .definition-strip small { display: block; }
.definition-strip small { color: var(--muted); }
@media (max-width: 900px) { .planet-grid { grid-template-columns: repeat(2, 1fr); } .planet-detail { grid-template-columns: repeat(2,1fr); } .planet-detail > div:first-child { grid-column: 1 / -1; } .dwarf-grid { grid-template-columns: repeat(2, 1fr); } .disk-stage { grid-template-columns: 1fr 120px 1fr; } }
@media (max-width: 600px) { .planet-grid, .dwarf-grid, .definition-strip { grid-template-columns: 1fr; } .planet-detail { grid-template-columns: 1fr 1fr; } .scale-controls { align-items: stretch; flex-direction: column; } .disk-stage { grid-template-columns: 1fr; min-height: 640px; } .ratio-readout { order: 2; } .disk-item:last-child { order: 3; } .distance-heading, .au-note { display: grid; } .distance-axis { overflow-x: auto; } .definition-strip > div { border-right: 0; border-bottom: 1px solid var(--line); } }

.planet-card{border-radius:var(--r);transition:border-color .18s ease,transform .18s ease,box-shadow .18s ease}.planet-card:hover{transform:translateY(-3px)}.planet-detail{border-radius:var(--r);overflow:hidden}.disk-stage{border-radius:var(--r)}

/* assets/site-shell.css */
/* The shared dock is independent of each subject's colors and navigation styles. */
body[data-knowledge-theme] { min-width: 0; }

body .site-knowledge-dock {
  position: fixed;
  right: max(18px, env(safe-area-inset-right));
  bottom: max(16px, env(safe-area-inset-bottom));
  z-index: 8;
  display: flex;
  align-items: center;
  gap: 5px;
  max-width: calc(100vw - 24px);
  margin: 0;
  padding: 5px;
  color: #f9f8f2;
  background: #173c32;
  border: 1px solid #386053;
  border-radius: 15px;
  box-shadow: 0 8px 28px rgba(19, 43, 34, .19);
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.4;
}
body .site-knowledge-dock a {
  position: static;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 44px;
  padding: 0 12px;
  color: #f9f8f2;
  background: transparent;
  border: 0;
  border-radius: 10px;
  text-decoration: none;
  white-space: nowrap;
  font-size: 13px;
  font-weight: 650;
  letter-spacing: 0;
  box-shadow: none;
  transition: background-color 160ms ease;
}
body .site-knowledge-dock .site-review-link { color: #e2eee5; background: rgba(255, 255, 255, .08); }
body .site-knowledge-dock a:hover,
body .site-knowledge-dock a[aria-current="page"] { color: #fff; background: rgba(255, 255, 255, .17); }
body .site-knowledge-dock .site-dock-icon { display: inline-block; font-size: 18px; line-height: 1; }
body .site-knowledge-dock a:focus-visible { outline: 2px solid #fff3c7; outline-offset: -2px; }
body .site-dock-spacer {
  display: block;
  clear: both;
  height: calc(88px + env(safe-area-inset-bottom));
  flex: 0 0 calc(88px + env(safe-area-inset-bottom));
  pointer-events: none;
}
@media (max-width: 560px) {
  body .site-knowledge-dock { right: 12px; bottom: max(12px, env(safe-area-inset-bottom)); border-radius: 13px; }
  body .site-knowledge-dock a { gap: 5px; padding: 0 10px; font-size: 12px; }
}
@media print { body .site-knowledge-dock, body .site-dock-spacer { display: none; } }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
  }
}

/* assets/knowledge-theme.css */
/* Shared reading theme. Semantic red/green and illustration colors stay local. */
body[data-knowledge-theme="light"] {
  --knowledge-green: #245345;
  --knowledge-green-soft: #e8efe8;
  --knowledge-paper: #f7f6ef;
  --knowledge-surface: #fffef9;
  --knowledge-line: #dce2d8;
  --paper: var(--knowledge-paper);
  --paper-deep: #e9ecdf;
  --card: var(--knowledge-surface);
  --panel: var(--knowledge-surface);
  --sheet: var(--knowledge-surface);
  --ink: #203c32;
  --dim: #606c62;
  --muted: #606c62;
  --line: var(--knowledge-line);
  --line-soft: #e8ece3;
  --accent: var(--knowledge-green);
  --shadow: 0 8px 26px rgba(35, 61, 43, .045);
  --bs-paper: var(--knowledge-paper);
  --bs-sheet: var(--knowledge-surface);
  --bs-ink: #203c32;
  --bs-muted: #606c62;
  --bs-line: var(--knowledge-line);
  color-scheme: light;
  color: var(--ink);
  background: var(--knowledge-paper);
  background-attachment: scroll;
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body[data-knowledge-theme="light"] ::selection {
  color: #fffef9;
  background: var(--knowledge-green);
}

body[data-knowledge-theme="light"] :where(h1, h2, h3) {
  text-wrap: pretty;
}

body[data-knowledge-theme="light"] > header:not(.topic-hero):not(.series-bar) h1 {
  letter-spacing: .05em;
}

body[data-knowledge-theme="light"] > header:not(.topic-hero):not(.series-bar) h1::after {
  background: var(--knowledge-green);
  opacity: .4;
}

body[data-knowledge-theme="light"] :where(.card:not(.mastered):not(.right):not(.wrong):not(.correct):not(.incorrect), .panel, .info-card,
  .module-card, .progress-panel, .reader, .side-panel, .map-card, .story-card,
  .fc, .q-body, .verse, .fc-face, .quiz-card, .quiz-finish, .dialog) {
  border-radius: 15px;
  background: var(--knowledge-surface);
  box-shadow: 0 5px 22px rgba(35, 61, 43, .045);
}

body[data-knowledge-theme="light"] .card:not(.mastered):not(.right):not(.wrong):not(.correct):not(.incorrect):hover {
  border-color: #9ab5a1;
  box-shadow: 0 8px 26px rgba(35, 61, 43, .075);
  transform: translateY(-2px);
}

body[data-knowledge-theme="light"] :where(.course-nav, .study-nav, .series-bar) {
  background: rgba(247, 246, 239, .96);
  border-color: var(--knowledge-line);
}

body[data-knowledge-theme="light"] nav button,
body[data-knowledge-theme="light"] #pages button {
  border-radius: 10px;
  font-family: inherit;
  letter-spacing: 0;
}

body[data-knowledge-theme="light"] nav button:is(.on, .is-active),
body[data-knowledge-theme="light"] #pages button.on,
body[data-knowledge-theme="light"] .series-bar__nav a[aria-current="page"] {
  color: #fffef9;
  background: var(--knowledge-green);
  border-color: var(--knowledge-green);
  box-shadow: none;
}

body[data-knowledge-theme="light"] nav button:hover:not(.on):not(.is-active),
body[data-knowledge-theme="light"] #pages button:hover:not(.on) {
  color: var(--knowledge-green);
  background: var(--knowledge-green-soft);
  border-color: #b5c8b9;
}

body[data-knowledge-theme="light"] :where(.chapter-btn.is-active, button.chip.on) {
  color: var(--knowledge-green);
  background: var(--knowledge-green-soft);
  border-color: #b5c8b9;
}

body[data-knowledge-theme="light"] :where(.toolbar input, .search input,
  input[type="text"], input[type="search"], textarea):not([type="checkbox"]):not([type="radio"]) {
  background: var(--knowledge-surface);
  border-color: var(--knowledge-line);
  border-radius: 10px;
}

body[data-knowledge-theme="light"] :where(a, button, input, select, textarea, [tabindex]):focus-visible {
  outline: 3px solid #85ab8f;
  outline-offset: 3px;
}

/* Keep the shared dock's focus contrast against its dark background. */
body[data-knowledge-theme="light"] .site-knowledge-dock a:focus-visible {
  outline: 2px solid #fff3c7;
  outline-offset: -2px;
}

/* Review Center has a light reading surface; leave verdicts and ratings semantic. */
body[data-knowledge-theme="light"] :where(.review-card, .session-finish,
  .memory-model, .coverage-card, .privacy-card) {
  background: var(--knowledge-surface);
  border-color: var(--knowledge-line);
  border-radius: 15px;
  box-shadow: 0 5px 22px rgba(35, 61, 43, .045);
}

body[data-knowledge-theme="light"] .review-hero .hero-stats {
  border-radius: 15px;
  box-shadow: 0 5px 22px rgba(35, 61, 43, .045);
}

body[data-knowledge-theme="light"] .review-hero .hero-stats div {
  background: var(--knowledge-surface);
}

body[data-knowledge-theme="light"] .review-hero :where(.brand, h1),
body[data-knowledge-theme="light"] .review-layout :where(.session-heading h2, .memory-model h2) {
  font-family: inherit;
}

body[data-knowledge-theme="light"] .review-hero h1 em,
body[data-knowledge-theme="light"] .review-layout .side-kicker,
body[data-knowledge-theme="light"] .review-layout .session-heading p {
  color: var(--knowledge-green);
}

body[data-knowledge-theme="light"] .review-hero .brand > span {
  background: var(--knowledge-green);
  border-radius: 10px;
}

body[data-knowledge-theme="light"] .review-layout .session-track span {
  background: var(--knowledge-green);
}

/* Let the bit table scroll within its lesson column instead of widening the page. */
body[data-knowledge-theme="light"].binary-series .lesson-grid > * {
  min-width: 0;
}

@media (max-width: 800px) {
  body[data-knowledge-theme="light"].binary-series .lesson-grid {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 420px) {
  body[data-knowledge-theme="light"] #xunList {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 560px) {
  body[data-knowledge-theme="light"] > header:not(.topic-hero):not(.series-bar) h1 {
    letter-spacing: .03em;
  }
}