/* 动植物检疫学 · 互动讲义  —— 配色同视频（kit/style.py）：深青 + 琥珀，朱红只给禁止/退回销毁，绿给合格放行 */
:root {
  --paper: #F5F6F2; --card: #FFFFFF; --soft: #E4EAE6; --ink: #1B2624; --muted: #5F6A66;
  --teal: #0F4C47; --sea: #2C7A70; --amber: #C27A1A; --mark: #F3E2C0;
  --red: #B2342E; --red-bg: #F6DEDB; --green: #3D7A3A; --green-bg: #DDEBD9;
  --line: #D3DAD6; --shadow: 0 1px 2px rgba(15,40,36,.06), 0 6px 20px rgba(15,40,36,.06);
  --serif: "Noto Serif SC", "Songti SC", "STSong", serif;
  --sans: -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #111917; --card: #18221F; --soft: #22302C; --ink: #E4EAE6; --muted: #9AA6A1;
    --teal: #7CC4B8; --sea: #5FB0A3; --amber: #E3A64B; --mark: #3A2E17;
    --red: #EA7A70; --red-bg: #3B1E1B; --green: #8CC47F; --green-bg: #1E3220;
    --line: #2C3A36; --shadow: 0 1px 2px rgba(0,0,0,.3); color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #111917; --card: #18221F; --soft: #22302C; --ink: #E4EAE6; --muted: #9AA6A1;
  --teal: #7CC4B8; --sea: #5FB0A3; --amber: #E3A64B; --mark: #3A2E17;
  --red: #EA7A70; --red-bg: #3B1E1B; --green: #8CC47F; --green-bg: #1E3220;
  --line: #2C3A36; --shadow: 0 1px 2px rgba(0,0,0,.3); color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.75 var(--sans); }
a { color: var(--sea); }
button { font: inherit; color: inherit; cursor: pointer; }
h1, h2, h3 { font-family: var(--serif); line-height: 1.3; margin: 0; letter-spacing: .01em; }
b, strong { color: var(--teal); font-weight: 650; }
.wrap { max-width: 1240px; margin: 0 auto; padding: 0 20px; }
.eyebrow { font-size: 13px; letter-spacing: .12em; color: var(--amber); font-weight: 600; }
.muted { color: var(--muted); }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

/* ---------- 顶栏 ---------- */
.topbar { position: sticky; top: 0; z-index: 30; background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.topbar .wrap { display: flex; align-items: center; gap: 16px; height: 56px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-family: var(--serif); font-weight: 700; font-size: 17px; }
.seal { width: 30px; height: 30px; border-radius: 7px; background: var(--teal); color: var(--paper); display: grid; place-items: center; font-size: 16px; font-family: var(--serif); }
.topbar nav { margin-left: auto; display: flex; gap: 6px; align-items: center; }
.topbar nav a { text-decoration: none; color: var(--muted); padding: 6px 10px; border-radius: 8px; font-size: 15px; }
.topbar nav a:hover { background: var(--soft); color: var(--ink); }
.icon-btn { border: 1px solid var(--line); background: var(--card); border-radius: 8px; width: 36px; height: 36px; display: grid; place-items: center; }

/* ---------- 通用卡片与按钮 ---------- */
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; box-shadow: var(--shadow); }
.btn { display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--line); background: var(--card); border-radius: 9px; padding: 7px 14px; font-size: 15px; text-decoration: none; color: var(--ink); }
.btn:hover { border-color: var(--sea); }
.btn.primary { background: var(--teal); border-color: var(--teal); color: var(--paper); }
.btn.small { padding: 4px 10px; font-size: 14px; }
.chip { display: inline-block; font-size: 12.5px; padding: 1px 9px; border-radius: 99px; background: var(--soft); color: var(--muted); }
.chip.amber { background: var(--mark); color: var(--amber); }
kbd { font: 12px var(--sans); border: 1px solid var(--line); border-radius: 4px; padding: 0 5px; background: var(--card); }

/* ---------- 首页 ---------- */
.hero { padding: 56px 0 28px; display: grid; grid-template-columns: 1.25fr 1fr; gap: 40px; align-items: center; }
.hero h1 { font-size: clamp(30px, 4.4vw, 46px); margin: 10px 0 14px; }
.hero h1 em { font-style: normal; color: var(--amber); }
.hero .lead { font-size: 17px; color: var(--muted); max-width: 36em; }
.hero-stats { display: flex; gap: 26px; margin-top: 22px; flex-wrap: wrap; }
.hero-stats div { font-size: 14px; color: var(--muted); }
.hero-stats b { display: block; font: 700 28px/1.2 var(--serif); color: var(--teal); }
.searchbox { position: relative; display: block; }
.searchbox input { width: 100%; font: inherit; font-size: 16px; padding: 13px 16px 13px 42px; border-radius: 12px; border: 1.5px solid var(--line); background: var(--card); color: var(--ink); }
.searchbox input:focus { outline: none; border-color: var(--sea); box-shadow: 0 0 0 4px color-mix(in srgb, var(--sea) 18%, transparent); }
.searchbox::before { content: "⌕"; position: absolute; left: 15px; top: 50%; transform: translateY(-55%); line-height: 1; font-size: 21px; color: var(--muted); }
.search-panel { padding: 22px; }
.search-panel h2 { font-size: 20px; margin-bottom: 6px; }
.search-tips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.search-tips button { border: 1px dashed var(--line); background: none; border-radius: 99px; padding: 2px 11px; font-size: 13.5px; color: var(--muted); }
.results { margin-top: 12px; max-height: 430px; overflow: auto; }
.result { display: block; padding: 9px 10px; border-radius: 9px; text-decoration: none; color: var(--ink); font-size: 14.5px; line-height: 1.6; }
.result:hover { background: var(--soft); }
.result small { display: block; color: var(--muted); font-size: 12.5px; }
.result mark { background: var(--mark); color: inherit; border-radius: 3px; padding: 0 1px; }

.continue { margin: 6px 0 30px; padding: 18px 22px; display: flex; gap: 18px; align-items: center; flex-wrap: wrap; }
.continue .bar { flex: 1; min-width: 160px; }
.progress { height: 7px; border-radius: 9px; background: var(--soft); overflow: hidden; }
.progress i { display: block; height: 100%; background: var(--sea); border-radius: 9px; }

.track { margin: 30px 0 40px; }
.track-head { display: flex; align-items: baseline; gap: 14px; margin-bottom: 14px; flex-wrap: wrap; }
.track-head h2 { font-size: 24px; }
.track-head .num { font: 700 15px var(--serif); color: var(--paper); background: var(--teal); border-radius: 6px; padding: 1px 8px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 14px; }
.lesson-card { padding: 18px 18px 16px; text-decoration: none; color: var(--ink); display: flex; flex-direction: column; gap: 6px; transition: transform .15s, border-color .15s; }
.lesson-card:hover { transform: translateY(-2px); border-color: var(--sea); }
.lesson-card .top { display: flex; justify-content: space-between; align-items: center; font-size: 13px; color: var(--muted); }
.lesson-card h3 { font-size: 18px; }
.lesson-card p { margin: 0; font-size: 14.5px; color: var(--muted); flex: 1; }
.lesson-card .foot { display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--muted); }
.lesson-card .foot .progress { flex: 1; }
.lesson-card.featured { border: 1.5px solid var(--amber); }

footer { border-top: 1px solid var(--line); margin-top: 50px; padding: 26px 0 40px; color: var(--muted); font-size: 13.5px; }
footer p { margin: 4px 0; }

/* ---------- 课程页 ---------- */
.lesson-hero { padding-top: 30px; padding-bottom: 18px; display: grid; grid-template-columns: 1fr 340px; gap: 30px; align-items: end; }
.lesson-hero h1 { font-size: clamp(26px, 3.6vw, 38px); margin: 6px 0 10px; }
.lesson-hero .summary { color: var(--muted); margin: 0; }
.goals { padding: 16px 18px; font-size: 14.5px; }
.goals h2 { font-size: 15px; margin-bottom: 6px; font-family: var(--sans); color: var(--teal); }
.goals ol { margin: 0; padding-left: 20px; }
.goals li { margin: 2px 0; }

.secnav { position: sticky; top: 56px; z-index: 20; background: var(--paper); border-bottom: 1px solid var(--line); }
.secnav .wrap { display: flex; gap: 6px; overflow-x: auto; padding-top: 8px; padding-bottom: 8px; scrollbar-width: none; }
.secnav button { flex: none; border: 1px solid var(--line); background: var(--card); border-radius: 99px; padding: 3px 12px; font-size: 13.5px; white-space: nowrap; color: var(--muted); }
.secnav button.on { background: var(--teal); border-color: var(--teal); color: var(--paper); }
.secnav button.done::after { content: " ✓"; }

.stage { display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(0, 1fr); gap: 26px; align-items: start; padding-top: 18px; }
.player { position: sticky; top: 108px; }
.player video { width: 100%; aspect-ratio: 16/9; background: #0b1412; border-radius: 12px; display: block; }
.player-tools { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin: 10px 0; font-size: 14px; }
.toggle { display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--line); background: var(--card); border-radius: 99px; padding: 3px 11px; font-size: 13.5px; }
.toggle[aria-pressed="true"] { background: var(--mark); border-color: var(--amber); color: var(--amber); }
.player-tools .time { margin-left: auto; color: var(--muted); font-variant-numeric: tabular-nums; }

.transcript { max-height: calc(100vh - 108px - 56.25vw * .5 - 120px); min-height: 180px; overflow: auto; padding: 8px; scroll-behavior: smooth; }
@media (min-width: 1240px) { .transcript { max-height: calc(100vh - 108px - 360px - 70px); } }
.transcript h4 { margin: 10px 8px 4px; font: 600 13px var(--sans); color: var(--amber); letter-spacing: .06em; }
.line { display: block; width: 100%; text-align: left; border: 0; background: none; padding: 6px 10px; border-radius: 8px; font-size: 15px; line-height: 1.65; color: var(--muted); }
.line:hover { background: var(--soft); color: var(--ink); }
.line.now { background: var(--mark); color: var(--ink); }
.line .en { display: block; font-size: 13.5px; color: var(--muted); }
.line.ask { border-left: 3px solid var(--amber); }
.line .ts { font-size: 11.5px; color: var(--muted); margin-right: 6px; font-variant-numeric: tabular-nums; }

.section { padding: 22px 22px 18px; margin-bottom: 18px; scroll-margin-top: 120px; transition: border-color .2s; }
.section.on { border-color: var(--sea); }
.section-head { display: flex; gap: 10px; align-items: start; justify-content: space-between; }
.section h2 { font-size: 21px; }
.section .play { flex: none; }
.points { margin: 12px 0 0; padding-left: 0; list-style: none; }
.points li { position: relative; padding-left: 18px; margin: 7px 0; }
.points li::before { content: ""; position: absolute; left: 3px; top: .72em; width: 6px; height: 6px; border-radius: 2px; background: var(--amber); }
.block { margin-top: 16px; }
.block > h3 { font: 600 14px var(--sans); color: var(--teal); margin-bottom: 8px; display: flex; gap: 8px; align-items: center; }
.block > h3::before { content: ""; width: 14px; height: 2px; background: var(--amber); }

.timeline { list-style: none; margin: 0; padding: 0 0 0 4px; border-left: 2px solid var(--soft); }
.timeline li { position: relative; padding: 4px 0 8px 18px; font-size: 14.5px; }
.timeline li::before { content: ""; position: absolute; left: -7px; top: 11px; width: 12px; height: 12px; border-radius: 50%; background: var(--card); border: 2px solid var(--sea); }
.timeline b { font-family: var(--serif); margin-right: 8px; }

.laws { display: grid; gap: 10px; }
.law { display: grid; grid-template-columns: 1fr auto 1fr; gap: 10px; align-items: center; font-size: 14px; border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; }
.law .old { color: var(--muted); text-decoration: line-through; text-decoration-color: var(--red); }
.law .old.none { text-decoration: none; }
.law .arrow { color: var(--amber); font-weight: 700; }
.law .now b { display: block; }
.law .note { grid-column: 1 / -1; font-size: 13px; color: var(--muted); border-top: 1px dashed var(--line); padding-top: 6px; }

.terms { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 8px; }
.term { perspective: 800px; border: 0; background: none; padding: 0; height: 112px; text-align: left; }
.term .in { position: relative; width: 100%; height: 100%; transition: transform .5s; transform-style: preserve-3d; }
.term.flip .in { transform: rotateY(180deg); }
.term .f, .term .b { position: absolute; inset: 0; backface-visibility: hidden; border-radius: 10px; border: 1px solid var(--line); padding: 10px 12px; display: flex; flex-direction: column; justify-content: center; }
.term .f { background: var(--soft); font: 700 16px var(--serif); color: var(--teal); }
.term .f small { font: 12px var(--sans); color: var(--muted); margin-top: 4px; }
.term .b { background: var(--card); transform: rotateY(180deg); font-size: 13.5px; line-height: 1.55; }

.flow { display: flex; gap: 0; overflow-x: auto; padding-bottom: 4px; }
.flow button { flex: 1; min-width: 92px; border: 1px solid var(--line); background: var(--card); padding: 8px 8px; font-size: 13.5px; position: relative; }
.flow button:first-child { border-radius: 9px 0 0 9px; } .flow button:last-child { border-radius: 0 9px 9px 0; }
.flow button + button { border-left: 0; }
.flow button.on { background: var(--teal); color: var(--paper); border-color: var(--teal); }
.flow-detail { margin-top: 8px; font-size: 14.5px; background: var(--soft); border-radius: 9px; padding: 9px 12px; min-height: 2.6em; }

.check { background: var(--soft); border-radius: 12px; padding: 14px 16px; }
.check p { margin: 0 0 8px; font-weight: 600; }
.opts { display: grid; gap: 6px; }
.opt { text-align: left; border: 1.5px solid var(--line); background: var(--card); border-radius: 9px; padding: 7px 12px; font-size: 14.5px; }
.opt:hover:not([disabled]) { border-color: var(--sea); }
.opt.right { border-color: var(--green); background: var(--green-bg); }
.opt.wrong { border-color: var(--red); background: var(--red-bg); }
.why { margin-top: 8px; font-size: 14px; }
.why.good::before { content: "✓ "; color: var(--green); font-weight: 700; }
.why.bad::before { content: "✗ "; color: var(--red); font-weight: 700; }

/* ---------- 互动实验（demos.js） ---------- */
.demo { border: 1.5px solid var(--sea); border-radius: 14px; padding: 16px; background: color-mix(in srgb, var(--sea) 5%, var(--card)); }
.demo-head { display: flex; justify-content: space-between; gap: 10px; align-items: baseline; flex-wrap: wrap; }
.demo-head h3 { font-size: 18px; }
.demo-head h3::before { content: "检疫现场 · "; font: 600 12.5px var(--sans); color: var(--amber); letter-spacing: .08em; vertical-align: 2px; }
.demo .hint { font-size: 13.5px; color: var(--muted); margin: 4px 0 12px; }
.demo .score { font-size: 13.5px; color: var(--muted); }

.case-text { background: var(--card); border-radius: 10px; padding: 12px 14px; border-left: 3px solid var(--sea); font-size: 15px; }
.case-text.good { border-left-color: var(--green); background: var(--green-bg); }
.case-text.bad { border-left-color: var(--red); background: var(--red-bg); }
.case-log { font-size: 13px; color: var(--muted); margin-bottom: 8px; }
.case-choices { display: grid; gap: 8px; margin-top: 10px; }

.sort-tray { display: flex; flex-wrap: wrap; gap: 8px; min-height: 44px; padding: 8px; border: 1px dashed var(--line); border-radius: 10px; }
.sort-item { border: 1px solid var(--line); background: var(--card); border-radius: 8px; padding: 5px 10px; font-size: 14px; cursor: grab; touch-action: none; user-select: none; }
.sort-item.sel { outline: 2.5px solid var(--amber); }
.sort-item.right { border-color: var(--green); background: var(--green-bg); cursor: default; }
.sort-item.wrong { animation: shake .35s; border-color: var(--red); }
.sort-item.dragging { opacity: .9; box-shadow: 0 8px 20px rgba(0,0,0,.18); position: fixed; z-index: 99; pointer-events: none; }
@keyframes shake { 25% { transform: translateX(-4px); } 75% { transform: translateX(4px); } }
.bins { display: grid; grid-template-columns: repeat(var(--n, 3), minmax(0, 1fr)); gap: 8px; margin-top: 10px; }
.bin { border: 1.5px solid var(--line); border-radius: 10px; padding: 8px; min-height: 120px; background: var(--card); display: flex; flex-direction: column; gap: 6px; }
.bin h4 { margin: 0; font-size: 14px; text-align: center; padding: 3px; border-radius: 6px; }
.bin.b0 h4 { background: var(--red-bg); color: var(--red); }
.bin.b1 h4 { background: var(--mark); color: var(--amber); }
.bin.b2 h4 { background: var(--green-bg); color: var(--green); }
.bins.neutral .bin h4 { background: var(--soft); color: var(--teal); }
.bin.hover { border-color: var(--sea); border-style: dashed; }
.sort-why { font-size: 13.5px; margin-top: 8px; min-height: 1.6em; }

.xray-wrap { display: grid; grid-template-columns: 1fr; gap: 10px; }
.xray-wrap canvas { width: 100%; border-radius: 10px; background: #0d1416; cursor: crosshair; display: block; }
.xray-side { font-size: 14px; display: grid; grid-template-columns: 150px minmax(0, 1fr); gap: 8px 12px; align-items: start; }
.xray-side .xray-ask { grid-row: span 3; grid-column: 2; }
@media (max-width: 600px) { .xray-side { grid-template-columns: 1fr; } .xray-side .xray-ask { grid-column: auto; grid-row: auto; } }
.legend span { display: inline-block; width: 11px; height: 11px; border-radius: 3px; margin-right: 6px; vertical-align: -1px; }
.xray-ask { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 10px; }
.xray-ask .opts { grid-template-columns: 1fr; }

.pet { display: grid; grid-template-columns: 1fr; gap: 12px; }
.pet-form { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 0 10px; }
.pet .seg button { white-space: nowrap; }
.pet > .verdict-slot { position: sticky; top: 108px; z-index: 2; box-shadow: 0 6px 14px -8px rgba(0,0,0,.25); border-radius: 12px; }
.pet fieldset { border: 1px solid var(--line); border-radius: 10px; padding: 8px 12px 10px; margin: 0 0 8px; background: var(--card); }
.pet legend { font-size: 13px; color: var(--teal); font-weight: 600; padding: 0 4px; }
.pet label { display: flex; align-items: center; gap: 8px; font-size: 14px; margin: 4px 0; }
.pet input[type=date], .pet select { font: inherit; font-size: 14px; padding: 2px 6px; border: 1px solid var(--line); border-radius: 6px; background: var(--paper); color: var(--ink); }
.pet .seg { display: inline-flex; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.pet .seg button { border: 0; background: var(--card); padding: 3px 10px; font-size: 13.5px; }
.pet .seg button.on { background: var(--teal); color: var(--paper); }
.verdict { border-radius: 12px; padding: 14px 16px; border: 2px solid var(--line); background: var(--card); }
.verdict .big { font: 700 22px var(--serif); }
.verdict.ok { border-color: var(--green); } .verdict.ok .big { color: var(--green); }
.verdict.iso { border-color: var(--amber); } .verdict.iso .big { color: var(--amber); }
.verdict.no { border-color: var(--red); } .verdict.no .big { color: var(--red); }
.verdict ul { margin: 8px 0 0; padding-left: 18px; font-size: 14px; }
.verdict li.x { color: var(--red); } .verdict li.v { color: var(--muted); }
.dateline { position: relative; height: 54px; margin: 12px 4px 4px; }
.dateline .axis { position: absolute; left: 0; right: 0; top: 26px; height: 2px; background: var(--line); }
.dateline .band { position: absolute; top: 20px; height: 14px; border-radius: 4px; opacity: .35; }
.dateline .pin { position: absolute; top: 18px; width: 2px; height: 18px; background: var(--ink); }
.dateline .pin span { position: absolute; top: -18px; left: 50%; transform: translateX(-50%); white-space: nowrap; font-size: 11.5px; color: var(--muted); }
.dateline .pin.arr { background: var(--amber); width: 3px; }
.dateline .pin.arr span { color: var(--amber); font-weight: 700; top: 22px; }
.pet-guess { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 8px; }

.pause-card { position: absolute; inset: auto 12px 56px 12px; background: var(--card); border: 2px solid var(--amber); border-radius: 12px; padding: 12px 14px; box-shadow: var(--shadow); font-size: 14.5px; z-index: 5; }
.pause-card textarea { width: 100%; min-height: 54px; font: inherit; font-size: 14px; border: 1px solid var(--line); border-radius: 8px; padding: 6px 8px; margin: 6px 0; background: var(--paper); color: var(--ink); }
.player-box { position: relative; }

.final { margin: 30px 0; padding: 24px; }
.final h2 { font-size: 24px; margin-bottom: 4px; }
.quiz-q { padding: 14px 0; border-top: 1px dashed var(--line); }
.quiz-q:first-of-type { border-top: 0; }
.quiz-q p { margin: 0 0 8px; }
.think { background: var(--mark); border-radius: 12px; padding: 14px 16px; margin-top: 14px; }
.notice { background: var(--mark); border-radius: 12px; padding: 12px 16px; font-size: 14.5px; margin: 12px 0; }

/* ---------- 窄屏 ---------- */
@media (max-width: 900px) {
  .hero, .lesson-hero { grid-template-columns: 1fr; gap: 18px; padding-top: 30px; }
  .stage { grid-template-columns: minmax(0, 1fr); gap: 14px; }
  .player { position: sticky; top: 56px; z-index: 15; background: var(--paper); padding: 6px 0 0; margin: 0 -16px; padding-left: 16px; padding-right: 16px; }
  .player video { border-radius: 8px; }
  .secnav { position: static; }
  .transcript { display: none; }
  .player-tools { margin: 6px 0 8px; flex-wrap: nowrap; overflow-x: auto; }
  .player-tools .time { display: none; }
  .toggle { white-space: nowrap; }
  .pet > .verdict-slot { position: static; }
  .bins { grid-template-columns: 1fr; }
  .bin { min-height: 64px; }
  .law { grid-template-columns: 1fr; } .law .arrow { display: none; }
}
@media (max-width: 600px) {
  .wrap { padding: 0 16px; }
  .section { padding: 16px 14px; }
  .topbar nav a.hide-sm { display: none; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; scroll-behavior: auto !important; } }

[hidden] { display: none !important; }
.stage > * { min-width: 0; }
.sec-tr { display: none; margin-top: 14px; border-top: 1px dashed var(--line); padding-top: 8px; }
.sec-tr summary { cursor: pointer; font-size: 14px; color: var(--sea); }
@media (max-width: 900px) { .sec-tr { display: block; } }

/* ---------- 首页立体书（assets/book/） ---------- */
.book { overflow-anchor: none; display: grid; grid-template-columns: minmax(0, 1fr) 380px; gap: 20px; padding-top: 22px; align-items: start; outline: none; }
.book:not(.ready) { display: none; }
.book-stage { position: relative; height: min(76vh, 680px); min-height: 440px; border-radius: 18px;
  background: radial-gradient(ellipse at 50% 40%, color-mix(in srgb, var(--soft) 70%, var(--paper)) 0%, var(--paper) 72%); }
.book-stage canvas { display: block; width: 100%; height: 100%; cursor: grab; border-radius: 18px; }
.book-stage canvas:active { cursor: grabbing; }
.book-panel { padding: 16px 20px 18px; align-self: center; }
.book-tabs { display: flex; gap: 2px; margin: -4px 0 12px; border-bottom: 1px solid var(--line); }
.book-tabs button { border: 0; background: none; font: 600 15px/1 var(--serif); color: var(--muted); padding: 9px 10px 10px; border-bottom: 3px solid transparent; margin-bottom: -1px; }
.book-tabs button[aria-current="true"] { color: var(--ink); border-bottom-color: var(--amber); }
.book-panel h2 { font-size: 23px; margin: 4px 0 6px; }
#book-why { margin: 0 0 6px; font-size: 15px; min-height: 3.4em; }
.book-cite { display: inline-block; font-size: 14px; font-weight: 600; text-decoration: none; margin-bottom: 10px; }
.book-cite:hover { text-decoration: underline; }
#book-controls { display: grid; gap: 8px; }
#book-controls .chips { display: flex; flex-wrap: wrap; gap: 6px; }
#book-controls .chips button { border: 1px solid var(--line); background: var(--card); border-radius: 99px; padding: 5px 12px; font-size: 14px; line-height: 1.4; }
#book-controls .chips button:hover { border-color: var(--sea); }
#book-controls .chips button[aria-pressed="true"] { background: var(--teal); border-color: var(--teal); color: var(--paper); }
#book-controls .chips button.warn { border-color: var(--amber); color: var(--amber); }
#book-controls .chips button[data-cat="organic"] { box-shadow: inset 0 -3px 0 #F08A24; }
#book-controls .chips button[data-cat="inorganic"] { box-shadow: inset 0 -3px 0 #3D8BEA; }
#book-controls .chips button[data-cat="mixed"] { box-shadow: inset 0 -3px 0 #3DBA6A; }
#book-controls .fume-check { font-size: 14.5px; display: flex; gap: 8px; align-items: center; }
#book-controls .fume-check input { accent-color: var(--teal); width: 16px; height: 16px; }
.chart { width: 100%; height: auto; display: block; }
.chart .bg { fill: var(--soft); }
.chart .min { stroke: var(--amber); stroke-width: 1.5; stroke-dasharray: 5 4; }
.chart .curve { fill: none; stroke: var(--teal); stroke-width: 2.5; stroke-linejoin: round; }
.chart .lbl { font-size: 11px; fill: var(--muted); }
.book-legend { font-size: 13.5px; color: var(--muted); margin: 10px 0 8px; line-height: 1.6; }
.book-lessons { display: flex; flex-wrap: wrap; gap: 4px 6px; margin-bottom: 12px; padding-top: 10px; border-top: 1px solid var(--line); }
.book-lessons a { font-size: 13.5px; text-decoration: none; color: var(--ink); background: var(--soft); border-radius: 7px; padding: 2px 8px; }
.book-lessons a b { color: var(--amber); margin-right: 5px; font-weight: 700; }
.book-lessons a:hover { background: var(--mark); }
.book-turn { display: flex; gap: 8px; }
.book-turn .btn:disabled { opacity: .4; cursor: default; }
@media (max-width: 960px) {
  .book { grid-template-columns: minmax(0, 1fr); gap: 12px; padding-top: 12px; }
  .book-stage { height: min(58svh, 92vw); min-height: 300px; }
}