/* 《大脑使用说明书》互联百科 —— 共享设计系统
   屏幕优先、单列阅读、自动暗/亮色、移动端触摸友好、无 CDN 依赖、可访问。 */

:root{
  --ink:#1c2230; --ink-soft:#44506a; --ink-faint:#6b7384;
  --bg:#fbfaf7; --bg-card:#ffffff; --line:#e7e3da; --line-soft:#f0ede6;
  /* 脊柱主色：预测误差 = 蓝紫渐变 */
  --spine-1:#5b54e0; --spine-2:#8a3fd1; --spine-ink:#3a2f9c;
  /* 六层辅助色 */
  --l0:#64748b; --l1:#2563eb; --l2:#0d9488; --l3:#db2777; --l4:#d97706; --l5:#7c3aed; --l6:#16a34a;
  --warn:#c2410c; --warn-bg:#fff4ec; --good:#15803d; --good-bg:#eefcf1;
  --note:#1d4ed8; --note-bg:#eef3ff; --debate:#a16207; --debate-bg:#fdf8e7; --myth:#b91c1c; --myth-bg:#fff1f0;
  --topbar-bg:rgba(251,250,247,.9);
  --tip-bg:#1f2430; --tip-ink:#f4f5f8; --tip-accent:#a9b4ff; --tip-line:transparent;
  --motif-panel:#ffffff;
  --radius:14px; --maxw:740px;
  --font:"Microsoft YaHei","PingFang SC","Noto Sans SC","Hiragino Sans GB",system-ui,sans-serif;
}

/* ===== 暗色：跟随系统（未手动指定时）+ 手动 data-theme=dark ===== */
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --ink:#e7e9ee; --ink-soft:#b6bdc9; --ink-faint:#8b94a3;
    --bg:#13151a; --bg-card:#1b1e25; --line:#2c313b; --line-soft:#23272f;
    --spine-1:#8e88ff; --spine-2:#c081ff; --spine-ink:#b6b0ff;
    --l0:#94a3b8; --l1:#5b9bff; --l2:#2dd4bf; --l3:#f472b6; --l4:#fbbf24; --l5:#a78bfa; --l6:#4ade80;
    --warn:#fb923c; --warn-bg:#3a2517; --good:#4ade80; --good-bg:#143021;
    --note:#93b4ff; --note-bg:#1a2540; --debate:#e3c75a; --debate-bg:#332b12; --myth:#f87171; --myth-bg:#3a1d1d;
    --topbar-bg:rgba(19,21,26,.88);
    --tip-bg:#2a2f3a; --tip-ink:#eef0f4; --tip-accent:#b9c2ff; --tip-line:#3a4150;
    --motif-panel:#f4f4f7;
  }
}
:root[data-theme="dark"]{
  --ink:#e7e9ee; --ink-soft:#b6bdc9; --ink-faint:#8b94a3;
  --bg:#13151a; --bg-card:#1b1e25; --line:#2c313b; --line-soft:#23272f;
  --spine-1:#8e88ff; --spine-2:#c081ff; --spine-ink:#b6b0ff;
  --l0:#94a3b8; --l1:#5b9bff; --l2:#2dd4bf; --l3:#f472b6; --l4:#fbbf24; --l5:#a78bfa; --l6:#4ade80;
  --warn:#fb923c; --warn-bg:#3a2517; --good:#4ade80; --good-bg:#143021;
  --note:#93b4ff; --note-bg:#1a2540; --debate:#e3c75a; --debate-bg:#332b12; --myth:#f87171; --myth-bg:#3a1d1d;
  --topbar-bg:rgba(19,21,26,.88);
  --tip-bg:#2a2f3a; --tip-ink:#eef0f4; --tip-accent:#b9c2ff; --tip-line:#3a4150;
  --motif-panel:#f4f4f7;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0; background:var(--bg); color:var(--ink);
  font-family:var(--font); font-size:18px; line-height:1.85;
  -webkit-font-smoothing:antialiased; text-rendering:optimizeLegibility;
  transition:background .2s, color .2s;
}

/* ---------- 顶部导航 ---------- */
.topbar{position:sticky; top:0; z-index:50; background:var(--topbar-bg);
  backdrop-filter:saturate(140%) blur(8px); -webkit-backdrop-filter:saturate(140%) blur(8px); border-bottom:1px solid var(--line);}
.topbar-inner{max-width:1080px; margin:0 auto; padding:10px 18px; display:flex; align-items:center; gap:12px; flex-wrap:wrap;}
.brand{font-weight:800; letter-spacing:.3px; color:var(--spine-ink); text-decoration:none; font-size:17px; white-space:nowrap;}
.brand small{display:block; font-weight:500; font-size:11px; color:var(--ink-faint); letter-spacing:1px;}
.navlayers{display:flex; gap:4px; flex-wrap:wrap; margin-left:auto; font-size:13px;}
.navlayers a{position:relative; text-decoration:none; color:var(--ink-soft); padding:6px 9px; border-radius:8px; white-space:nowrap;}
.navlayers a:hover{background:var(--line-soft); color:var(--ink);}
.navlayers a.active{background:var(--spine-ink); color:#fff;}
.navlayers a .dot{display:inline-block; width:7px; height:7px; border-radius:50%; margin-right:5px; vertical-align:middle;}

/* 主题切换按钮（由 app.js 注入） */
.themebtn{flex:0 0 auto; border:1px solid var(--line); background:var(--bg-card); color:var(--ink-soft);
  border-radius:9px; min-width:38px; height:34px; cursor:pointer; font-size:16px; line-height:1;
  display:inline-flex; align-items:center; justify-content:center; padding:0 8px;}
.themebtn:hover{color:var(--ink); border-color:var(--spine-1);}

/* ---------- 布局 ---------- */
.wrap{max-width:1080px; margin:0 auto; padding:0 18px; display:grid; grid-template-columns:minmax(0,1fr) 248px; gap:40px;}
@media(max-width:900px){ .wrap{grid-template-columns:1fr} .aside{order:2} }
.col{max-width:var(--maxw); width:100%; padding:8px 0 80px;}
.aside{position:sticky; top:64px; align-self:start; padding-top:26px; font-size:14px; height:max-content;}

/* ---------- 文章排版 ---------- */
.kicker{display:inline-block; font-size:12px; font-weight:700; letter-spacing:2px; padding:4px 10px; border-radius:999px; color:#fff; margin:30px 0 10px;}
h1.title{font-size:33px; line-height:1.3; margin:.1em 0 .3em; letter-spacing:.3px;}
.lede{font-size:20px; color:var(--ink-soft); line-height:1.7; margin:0 0 8px; font-weight:500;}
.col h2{font-size:24px; margin:1.7em 0 .5em; padding-top:.3em; border-top:1px solid var(--line-soft);}
.col h3{font-size:19px; margin:1.3em 0 .35em; color:var(--spine-ink);}
.col p{margin:.7em 0;}
.col a{color:var(--note); text-decoration:none; border-bottom:1px solid color-mix(in srgb, var(--note) 35%, transparent);}
.col a:hover{border-bottom-color:var(--note);}
.col ul,.col ol{padding-left:1.3em;} .col li{margin:.3em 0;}
.small{font-size:14px; color:var(--ink-faint);}

/* ---------- 术语 tooltip ---------- */
.term{border-bottom:1px dashed var(--spine-1); cursor:help; color:var(--spine-ink); font-weight:600; padding:0 1px;}
.term:focus{outline:2px solid var(--spine-1); outline-offset:2px; border-radius:3px;}
.tip{position:fixed; z-index:100; max-width:300px; background:var(--tip-bg); color:var(--tip-ink); border:1px solid var(--tip-line);
  font-size:13.5px; line-height:1.6; padding:10px 13px; border-radius:10px; box-shadow:0 10px 30px rgba(0,0,0,.32);
  pointer-events:none; opacity:0; transform:translateY(4px); transition:opacity .12s, transform .12s; font-weight:400;}
.tip.show{opacity:1; transform:translateY(0);}
.tip b{color:var(--tip-accent);}
.tip .more{display:block; margin-top:6px; color:var(--tip-accent); font-size:12px; opacity:.85;}

/* ---------- 呼应卡（核心互联组件） ---------- */
.echo{background:color-mix(in srgb, var(--spine-1) 8%, var(--bg-card)); border:1px solid color-mix(in srgb, var(--spine-1) 28%, transparent);
  border-radius:var(--radius); padding:14px 16px; margin-bottom:18px;}
.echo h4{margin:0 0 8px; font-size:13px; letter-spacing:1px; color:var(--spine-ink); text-transform:uppercase;}
.echo ul{list-style:none; margin:0; padding:0;}
.echo li{margin:7px 0; font-size:13.5px; line-height:1.5;}
.echo a{display:block; color:var(--ink); text-decoration:none; border-left:3px solid var(--spine-1); padding-left:9px;}
.echo a:hover{color:var(--spine-ink);}
.echo a em{display:block; font-style:normal; color:var(--ink-faint); font-size:12px;}

/* ---------- callouts ---------- */
.callout{border-radius:var(--radius); padding:14px 16px 14px 46px; margin:18px 0; position:relative; font-size:16px; line-height:1.7;}
.callout::before{position:absolute; left:14px; top:13px; font-size:19px;}
.callout b{display:block; margin-bottom:2px;}
.c-key{background:var(--good-bg); border:1px solid color-mix(in srgb, var(--good) 40%, transparent);} .c-key::before{content:"🔑";}
.c-tldr{background:var(--note-bg); border:1px solid color-mix(in srgb, var(--note) 40%, transparent);} .c-tldr::before{content:"💡";}
.c-warn{background:var(--warn-bg); border:1px solid color-mix(in srgb, var(--warn) 40%, transparent);} .c-warn::before{content:"⚠️";}
.c-debate{background:var(--debate-bg); border:1px solid color-mix(in srgb, var(--debate) 45%, transparent);} .c-debate::before{content:"⚖️";}
.c-term{background:color-mix(in srgb, var(--spine-1) 10%, var(--bg-card)); border:1px solid color-mix(in srgb, var(--spine-1) 30%, transparent);} .c-term::before{content:"📖";}

/* ---------- 误区 myth vs fact ---------- */
.mf{display:grid; grid-template-columns:1fr 1fr; gap:0; border:1px solid var(--line); border-radius:var(--radius); overflow:hidden; margin:18px 0;}
.mf>div{padding:13px 15px; font-size:15px; line-height:1.65;}
.mf .myth{background:var(--myth-bg); border-right:1px solid var(--line);}
.mf .myth b,.mf .fact b{display:block; font-size:12px; letter-spacing:1px; margin-bottom:4px;}
.mf .myth b{color:var(--myth);} .mf .fact b{color:var(--good);}
.mf .fact{background:var(--good-bg);}

/* ---------- 数据卡 ---------- */
.statcard{border:1px solid var(--line); border-left:4px solid var(--spine-1); border-radius:10px; padding:11px 14px; margin:12px 0; background:var(--bg-card);}
.statcard .num{font-size:22px; font-weight:800; color:var(--spine-ink); line-height:1.2;}
.statcard .claim{font-size:15px; margin:2px 0 4px;}
.statcard .src{font-size:12.5px; color:var(--ink-faint);}
.statcard .src::before{content:"来源 · ";}
.statcard .caveat{font-size:12.5px; color:var(--warn); margin-top:3px;}
.statcard .caveat::before{content:"注意 · ";}

/* ---------- 母题 SVG（暗色下放在浅色面板上保证可读） ---------- */
.motif{display:block; margin:0 auto; max-width:560px; width:100%;}
.cxfig .motif{max-width:640px;}
figure{margin:22px 0; text-align:center; background:var(--motif-panel); border:1px solid var(--line); border-radius:12px; padding:14px 12px 6px;}
figcaption{font-size:13px; color:var(--ink-faint); margin-top:8px; padding:0 6px;}
.motif + figcaption, figure .motif ~ figcaption{color:var(--ink-faint);}
/* 仅含母题图的 figure 才套浅色面板；纯说明 figure 退回透明 */
figure:not(:has(.motif)){background:none; border:none; padding:0;}

/* ---------- 首页 hero / 层卡 ---------- */
.hero{padding:54px 0 26px; text-align:center;}
.hero h1{font-size:42px; line-height:1.2; margin:.1em 0; background:linear-gradient(120deg,var(--spine-1),var(--spine-2)); -webkit-background-clip:text; background-clip:text; color:transparent;}
.hero p{font-size:20px; color:var(--ink-soft); max-width:620px; margin:14px auto;}
.layers{display:grid; grid-template-columns:repeat(auto-fit,minmax(250px,1fr)); gap:16px; margin:30px 0;}
.layercard{display:block; text-decoration:none; color:inherit; background:var(--bg-card); border:1px solid var(--line); border-radius:var(--radius); padding:18px; transition:transform .12s, box-shadow .12s;}
.layercard:hover{transform:translateY(-3px); box-shadow:0 12px 28px rgba(60,50,120,.14);}
.layercard .lyr{font-size:12px; font-weight:800; letter-spacing:2px;}
.layercard h3{margin:.3em 0; font-size:19px;}
.layercard p{margin:0; font-size:14px; color:var(--ink-faint);}
.layercard ol{margin:8px 0 0; padding-left:1.2em; font-size:13.5px; color:var(--ink-soft);}

/* ---------- footer ---------- */
.foot{border-top:1px solid var(--line); margin-top:40px; background:var(--line-soft);}
.foot-inner{max-width:1080px; margin:0 auto; padding:26px 18px; font-size:13px; color:var(--ink-faint); display:flex; gap:24px; flex-wrap:wrap; justify-content:space-between;}
.foot a{color:var(--ink-soft);}
.prevnext{display:flex; justify-content:space-between; gap:14px; margin:40px 0 0;}
.prevnext a{flex:1; border:1px solid var(--line); border-radius:12px; padding:12px 15px; text-decoration:none; color:var(--ink); background:var(--bg-card);}
.prevnext a:hover{border-color:var(--spine-1);}
.prevnext .lab{font-size:12px; color:var(--ink-faint);}
.prevnext .nx{text-align:right;}

/* ============ 移动端适配（触摸友好） ============ */
@media(max-width:680px){
  body{font-size:16.5px; line-height:1.8;}
  .topbar-inner{padding:8px 12px; gap:8px;}
  .brand{font-size:15px;}
  .brand small{display:none;}
  .themebtn{margin-left:auto;}
  /* 层导航：整行横向滑动，不再换行堆高 */
  .navlayers{order:3; width:100%; margin-left:0; flex-wrap:nowrap; overflow-x:auto; -webkit-overflow-scrolling:touch;
    padding-bottom:3px; scrollbar-width:none; gap:6px;}
  .navlayers::-webkit-scrollbar{display:none;}
  .navlayers a{flex:0 0 auto; min-height:40px; display:inline-flex; align-items:center; padding:0 12px;}
  .wrap{padding:0 14px; gap:22px;}
  .col{padding-bottom:60px;}
  .aside{position:static; top:auto; padding-top:6px;}
  .kicker{margin-top:20px;}
  h1.title{font-size:26px;}
  .lede{font-size:17.5px;}
  .col h2{font-size:20px;}
  .col h3{font-size:17px;}
  .hero{padding:40px 0 18px;}
  .hero h1{font-size:31px;}
  .hero p{font-size:17px;}
  .layers{grid-template-columns:1fr;}
  .mf{grid-template-columns:1fr;}
  .mf .myth{border-right:none; border-bottom:1px solid var(--line);}
  .prevnext{flex-direction:column;}
  .prevnext .nx{text-align:left;}
  .callout{font-size:15.5px;}
  /* 触摸：术语点按弹出的说明改成屏幕底部"说明条"，不挡正文 */
  .tip{left:10px !important; right:10px; top:auto !important; bottom:12px; max-width:none; width:auto;
    font-size:15px; padding:14px 16px; box-shadow:0 -6px 26px rgba(0,0,0,.3);}
}
@media(max-width:430px){
  .hero h1{font-size:27px;}
  h1.title{font-size:23px;}
}

/* 减少动效偏好 */
@media (prefers-reduced-motion: reduce){ *{transition:none !important; scroll-behavior:auto !important;} }