:root{
  --bg:#080c16;--surface:rgba(15,21,36,.92);--fg:#e2e8f0;--fg-muted:#8892a6;
  --border:rgba(255,255,255,.08);--border-strong:rgba(255,255,255,.14);
  --accent:#00d4ff;--good:#34d399;--bad:#f87171;
  --shell:480px;--bar-h:56px;--top-h:48px;
  --font:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",system-ui,sans-serif
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%;max-width:100%;overflow:hidden;background:var(--bg);color:var(--fg);font-family:var(--font);-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
.shell{max-width:var(--shell);height:100%;margin:0 auto;display:flex;flex-direction:column;position:relative;background:var(--bg)}
.topbar{flex:0 0 var(--top-h);height:var(--top-h);display:flex;align-items:center;justify-content:space-between;gap:8px;padding:0 14px;border-bottom:1px solid var(--border);background:rgba(8,12,22,.96)}
.brand{display:flex;align-items:center;gap:8px;font-weight:700;font-size:.88rem;color:#f1f5f9;min-width:0}
.brand .mark{width:22px;height:20px;flex:0 0 auto;display:block;object-fit:contain;background:none;clip-path:none;border:0}
.brand small{display:block;font-size:.62rem;font-weight:500;color:var(--fg-muted)}
.progress{font-size:.78rem;color:var(--fg-muted);white-space:nowrap}
.progress b{color:var(--accent);font-weight:700}
.stage{flex:1;min-height:0;position:relative;overflow:hidden;width:100%;touch-action:pan-y}
.deck{height:100%;width:100%;display:flex;transition:transform .22s ease;will-change:transform}
.card{flex:0 0 100%;width:100%;max-width:100%;min-width:0;height:100%;padding:12px 16px 10px;overflow:hidden;display:flex;flex-direction:column;box-sizing:border-box}
.card-inner{flex:1;min-height:0;background:var(--surface);border:1px solid var(--border);border-radius:14px;padding:12px 12px 10px;display:flex;flex-direction:column;gap:6px;overflow:hidden}
.kicker{font-size:.7rem;font-weight:700;letter-spacing:.06em;color:var(--accent);text-transform:uppercase}
.card h1,.card h2{font-size:1.12rem;font-weight:750;color:#f1f5f9;line-height:1.3}
.card p,.card li{font-size:.86rem;color:var(--fg-muted);line-height:1.55}
.card ul{margin:0 0 0 1em;display:grid;gap:4px}
.note{font-size:.78rem;color:var(--fg-muted);background:rgba(0,212,255,.06);border:1px solid rgba(0,212,255,.16);border-radius:10px;padding:8px 10px;line-height:1.5}
.cmp{border-radius:10px;border:1px solid var(--border);overflow:visible;margin-top:2px;flex:0 0 auto}
.cmp-head{padding:5px 10px;font-size:.72rem;font-weight:700}
.cmp.bad .cmp-head{background:rgba(248,113,113,.12);color:var(--bad)}
.cmp.good .cmp-head{background:rgba(52,211,153,.12);color:var(--good)}
.cmp pre{margin:0;padding:8px 10px;white-space:pre-wrap;overflow-wrap:anywhere;word-break:break-word;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.72rem;line-height:1.4;color:#dbe4f0;background:rgba(0,0,0,.22);max-height:none;overflow:visible;height:auto}
.prompt{border:1px solid var(--border);border-radius:10px;overflow:hidden;background:rgba(0,0,0,.16);display:flex;flex-direction:column;min-height:0;flex:1 1 auto}
.prompt-bar{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:7px 10px;border-bottom:1px solid var(--border);background:rgba(255,255,255,.03)}
.prompt-bar span{font-size:.72rem;color:var(--fg-muted);font-weight:600}
.prompt pre{margin:0;padding:8px 10px;white-space:pre-wrap;overflow-wrap:anywhere;word-break:break-word;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.72rem;line-height:1.4;color:#dbe4f0;background:rgba(0,0,0,.22);flex:1 1 auto;min-height:0;max-height:none;overflow:auto}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:10px 14px;border-radius:999px;font-size:.86rem;font-weight:650;border:0;cursor:pointer;font-family:inherit;transition:background .15s}
.btn-copy,.btn-accent{background:rgba(0,212,255,.16);color:var(--accent);border:1px solid rgba(0,212,255,.3)}
.btn-copy.copied{background:rgba(0,212,255,.3)}
.btn-primary{background:linear-gradient(135deg,#00d4ff,#3b9dff);color:#04121a}
.btn-ghost{background:rgba(255,255,255,.04);color:var(--fg);border:1px solid var(--border-strong)}
.btn-block{width:100%}
.btn-row{display:grid;gap:8px;margin-top:auto}
.choices{display:grid;gap:8px;margin-top:6px}
.choice{text-align:left;padding:11px 12px;border-radius:12px;border:1px solid var(--border);background:rgba(255,255,255,.03);color:#e2e8f0;font-size:.86rem;line-height:1.4;cursor:pointer;font-family:inherit}
.choice:active{transform:scale(.99)}
.choice.correct{border-color:rgba(52,211,153,.55);background:rgba(52,211,153,.12);color:var(--good)}
.choice.wrong{border-color:rgba(248,113,113,.55);background:rgba(248,113,113,.12);color:var(--bad)}
.choice:disabled{opacity:.95;cursor:default}
.feedback{display:none;margin-top:4px;padding:10px;border-radius:10px;font-size:.82rem;line-height:1.5;color:var(--fg-muted);background:rgba(0,212,255,.06);border:1px solid rgba(0,212,255,.15)}
.feedback.show{display:block}
.feedback b{color:#f1f5f9}
.actions{display:none;grid-template-columns:1fr 1fr;gap:8px;margin-top:10px}
.actions.show{display:grid}
.toolbar{flex:0 0 var(--bar-h);height:var(--bar-h);display:grid;grid-template-columns:1fr 1fr 1fr;gap:8px;align-items:center;padding:8px 12px calc(8px + env(safe-area-inset-bottom,0));border-top:1px solid var(--border);background:rgba(8,12,22,.98)}
.toolbar .btn{padding:10px 8px;font-size:.82rem}
.toolbar .btn:disabled{opacity:.35;pointer-events:none}

/* landing */
.landing .stage{overflow:auto;-webkit-overflow-scrolling:touch}
.hero-mini{padding:10px 2px 6px;text-align:center}
.hero-mini .kicker{margin-bottom:4px}
.hero-mini h1{font-size:1.25rem;font-weight:750;color:#f1f5f9;margin-bottom:4px}
.hero-mini p{font-size:.8rem;color:var(--fg-muted);line-height:1.45}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:8px;padding:4px 0 12px}
.tile{display:flex;flex-direction:column;gap:2px;padding:10px 10px;border-radius:12px;border:1px solid var(--border);background:var(--surface);min-height:72px}
.tile.ready{border-color:rgba(0,212,255,.28)}
.tile.soon{opacity:.55}
.tile .n{font-size:.68rem;font-weight:800;color:var(--accent)}
.tile.soon .n{color:var(--fg-muted)}
.tile strong{font-size:.82rem;color:#f1f5f9;line-height:1.25;font-weight:700}
.tile span{font-size:.68rem;color:var(--fg-muted);line-height:1.35}
.foot-tip{text-align:center;font-size:.72rem;color:var(--fg-muted);line-height:1.45;padding:0 8px 8px}

@media print{
  .shell *{display:none !important}
  body::before{content:"请用手机微信打开本课件";display:block;padding:48px 24px;text-align:center;color:#94a3b8}
}