/* 小學生科學站 — dark (full Mac curriculum) */
:root{
  color-scheme: dark;
  --bg:#0b1220;
  --card:#151c2c;
  --ink:#e5e7eb;
  --muted:#9ca3af;
  --brand:#60a5fa;
  --brand2:#fbbf24;
  --accent:#f472b6;
  --ok:#4ade80;
  --bad:#f87171;
  --line:rgba(148,163,184,.22);
  --shadow:0 12px 32px rgba(0,0,0,.35);
  --radius:18px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;font-family:"Noto Sans TC","PingFang TC","Microsoft JhengHei",sans-serif;
  background:
    radial-gradient(circle at top left,rgba(37,99,235,.35) 0,transparent 42%),
    radial-gradient(circle at 90% 10%,rgba(251,191,36,.16) 0,transparent 35%),
    linear-gradient(180deg,#0b1220 0%,#0f172a 100%);
  color:var(--ink);line-height:1.75;min-height:100vh;
}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto}
.wrap{max-width:980px;margin:0 auto;padding:20px 16px 88px}
.top{
  display:flex;flex-wrap:wrap;gap:12px;align-items:center;justify-content:space-between;
  margin-bottom:22px;
}
.brand{
  display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.25rem;color:var(--ink);
}
.logo{
  width:42px;height:42px;border-radius:14px;display:grid;place-items:center;
  background:linear-gradient(135deg,#2563eb,#60a5fa);color:#fff;font-size:1.3rem;
  box-shadow:var(--shadow);
}
.nav{display:flex;flex-wrap:wrap;gap:8px}
.nav a{
  background:rgba(21,28,44,.95);border:1px solid var(--line);padding:8px 12px;border-radius:999px;
  color:var(--ink);font-size:.92rem;box-shadow:0 2px 10px rgba(0,0,0,.25);
  min-height:44px;display:inline-flex;align-items:center;
}
.nav a:hover{border-color:rgba(96,165,250,.6);text-decoration:none}
.hero{
  background:linear-gradient(135deg,#1e3a8a,#2563eb 55%,#b45309);
  color:#fff;border-radius:28px;padding:28px 24px;box-shadow:var(--shadow);margin-bottom:24px;
}
.hero h1{margin:0 0 8px;font-size:clamp(1.6rem,4vw,2.3rem);line-height:1.25}
.hero p{margin:0;opacity:.95;font-size:1.05rem}
.hero-art{
  margin:0 0 18px;border-radius:24px;overflow:hidden;box-shadow:var(--shadow);
  background:#1e293b;
}
.hero-art img{display:block;width:100%;height:auto;aspect-ratio:16/9;object-fit:cover}
.group-title{
  margin:8px 0 12px;font-size:1.15rem;color:#93c5fd;
}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px;margin-bottom:22px}
.card{
  background:var(--card);border-radius:var(--radius);padding:0 0 16px;box-shadow:var(--shadow);
  border:1px solid var(--line);transition:transform .15s ease, box-shadow .15s ease, border-color .15s;
  overflow:hidden;display:block;color:inherit;
}
.card:hover{transform:translateY(-3px);box-shadow:0 16px 36px rgba(0,0,0,.45);text-decoration:none;border-color:rgba(96,165,250,.45)}
.card-img{display:block;width:100%;height:140px;object-fit:cover;background:#1e293b}
.card .emoji{font-size:1.6rem;display:inline-block;margin:12px 16px 0}
.card h2{margin:4px 16px 6px;font-size:1.15rem;color:#f3f4f6}
.card p{margin:0 16px;color:var(--muted);font-size:.95rem}
.panel{
  background:var(--card);border-radius:24px;padding:22px 18px;box-shadow:var(--shadow);
  border:1px solid var(--line);margin-bottom:18px;
}
.panel h1{margin-top:0;font-size:clamp(1.5rem,3.5vw,2rem);color:#f9fafb}
.panel h2{font-size:1.2rem;color:#93c5fd;margin:0 0 8px}
.topic-head{
  display:flex;flex-wrap:wrap;gap:12px;align-items:flex-start;justify-content:space-between;
  margin-bottom:8px;
}
.topic-head h1{margin:0;flex:1 1 220px}
.speak-bar{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.speak-tools{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.speak-ctrl{
  display:inline-flex;align-items:center;gap:6px;
  background:rgba(21,28,44,.95);color:#fda4cf;border:2px solid rgba(244,114,182,.45);
  border-radius:14px;padding:4px 10px;min-height:44px;
  font-weight:700;font-size:.88rem;
}
.speak-ctrl span{white-space:nowrap}
.speak-ctrl select{
  border:0;background:transparent;font-family:inherit;font-weight:700;
  color:#fda4cf;font-size:.88rem;max-width:11.5rem;min-height:36px;
  cursor:pointer;
}
.speak-hint{
  flex:1 1 100%;margin:4px 0 0;font-size:.82rem;font-weight:600;
  color:#fda4cf;background:rgba(157,23,77,.35);border-radius:12px;padding:8px 10px;
}
.hero .speak-hint{background:rgba(255,255,255,.18);color:#fff}
button{font-family:inherit;cursor:pointer}
button:focus-visible, a:focus-visible, input:focus-visible{
  outline:3px solid #93c5fd;outline-offset:2px;
}
.speak-btn, .speak-mini, .speak-stop, button.primary{
  min-height:44px;border:0;border-radius:14px;padding:8px 14px;
  font-weight:700;font-size:.95rem;display:inline-flex;align-items:center;gap:6px;
  transition:transform .15s ease, filter .15s ease, background .15s ease;
}
.speak-btn:hover, .speak-mini:hover, .speak-stop:hover, button.primary:hover{filter:brightness(1.08)}
.speak-btn:active, .speak-mini:active, button.primary:active{transform:scale(.97)}
.speak-btn{
  background:linear-gradient(180deg,#fb7185,#ec4899);color:#fff;
  box-shadow:0 6px 0 #9d174d, 0 10px 18px rgba(236,72,153,.35);
}
a.speak-btn{color:#fff}
.speak-mini{
  background:rgba(21,28,44,.95);color:#fda4cf;border:2px solid rgba(244,114,182,.45);
  min-height:40px;padding:6px 12px;font-size:.88rem;margin:0 0 10px;
}
.speak-stop{background:#374151;color:#fff}
button.primary{
  background:var(--brand);color:#0b1220;box-shadow:0 4px 0 #1e40af;
}
.lesson{
  display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);
  gap:18px;align-items:center;margin:22px 0;padding:12px;
  border-radius:20px;background:rgba(15,23,42,.65);
}
.lesson.reverse{grid-template-columns:minmax(0,1fr) minmax(0,1.05fr)}
.lesson.reverse .lesson-fig{order:2}
.lesson.wide{grid-template-columns:1fr;background:transparent;padding:0}
.lesson-fig{
  margin:0;border-radius:18px;overflow:hidden;box-shadow:var(--shadow);background:#1e293b;
}
.lesson-fig img{display:block;width:100%;height:auto;aspect-ratio:4/3;object-fit:cover}
.lesson.wide .lesson-fig img{aspect-ratio:16/9}
.lesson-fig.portrait{max-width:340px;margin-inline:auto}
.lesson-fig.portrait img{aspect-ratio:3/4}
.lesson-body p{margin:0 0 10px}
.lesson-body ul, .lesson-body ol{margin:8px 0 12px;padding-left:1.2em}
.speak-block.speaking, .lesson.speaking, .tip.speaking{
  outline:3px solid rgba(244,114,182,.7);background:rgba(157,23,77,.25);
}
.tip{
  background:rgba(6,78,59,.35);border:1px solid rgba(52,211,153,.35);border-radius:16px;padding:12px 14px;margin:14px 0;
}
.tip strong{color:#6ee7b7}
.fact{
  background:rgba(124,45,18,.35);border:1px solid rgba(251,146,60,.4);border-radius:16px;padding:12px 14px;margin:14px 0;
}
.fact strong{color:#fdba74}
.steps{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:10px;margin:12px 0 4px;
}
.step{
  background:rgba(30,58,138,.35);border:1px solid rgba(96,165,250,.35);border-radius:14px;padding:12px;
}
.step .n{
  display:inline-grid;place-items:center;width:28px;height:28px;border-radius:50%;
  background:#2563eb;color:#fff;font-weight:800;margin-right:6px;font-size:.9rem;
}
.step h3{margin:8px 0 4px;font-size:1rem}
.step p{margin:0;color:var(--muted);font-size:.92rem}
.swatches{display:flex;flex-wrap:wrap;gap:6px;margin:10px 0}
.swatch{
  flex:1 1 70px;min-height:44px;border-radius:12px;display:grid;place-items:center;
  color:#fff;font-weight:800;font-size:.9rem;text-shadow:0 1px 2px rgba(0,0,0,.35);
}
.quiz{
  background:rgba(30,58,138,.35);border:1px solid rgba(96,165,250,.35);border-radius:16px;padding:14px;margin-top:18px;
}
.quiz h2{margin-top:0;color:#93c5fd}
.q{margin:14px 0;padding-bottom:10px;border-bottom:1px dashed rgba(96,165,250,.35)}
.q:last-of-type{border-bottom:0}
.q label{display:block;margin:6px 0;cursor:pointer;min-height:32px}
.result{margin-top:12px;font-weight:700}
.result.ok{color:var(--ok)}
.result.bad{color:var(--bad)}
.footer{margin-top:28px;color:var(--muted);font-size:.9rem;text-align:center}
.back{display:inline-block;margin-bottom:12px;min-height:44px}
.speak-dock{
  position:fixed;left:50%;bottom:16px;transform:translateX(-50%);
  background:#111827;color:#fff;border-radius:999px;padding:10px 12px 10px 18px;
  display:flex;align-items:center;gap:12px;box-shadow:0 12px 30px rgba(0,0,0,.45);
  z-index:20;max-width:calc(100% - 24px);
}
.speak-dock[hidden]{display:none !important}
.no-speech{color:var(--muted);font-size:.9rem}
.nav a.is-active{border-color:#60a5fa;background:rgba(37,99,235,.25);color:#93c5fd}
.k-meta{margin:0 0 8px;color:var(--muted);display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.badge{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:28px;padding:2px 10px;border-radius:999px;font-size:.8rem;font-weight:800;
  color:#fff;
}
.card .badge{margin:10px 16px 0}
.g-g4{background:#2563eb}
.g-g5{background:#16a34a}
.g-g6{background:#d97706}
.g-j1{background:#7c3aed}
.g-j2{background:#db2777}
.filters{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 16px}
.filter{
  min-height:44px;border:1px solid var(--line);background:rgba(21,28,44,.95);border-radius:999px;
  padding:8px 14px;font-weight:700;color:var(--ink);box-shadow:0 2px 10px rgba(0,0,0,.25);
}
.filter.is-on{background:#1d4ed8;color:#fff;border-color:#1d4ed8}
.pager{
  display:flex;flex-wrap:wrap;justify-content:space-between;gap:10px;align-items:center;
  margin-top:22px;padding-top:12px;border-top:1px dashed var(--line);
}
.pager a{min-height:44px;display:inline-flex;align-items:center}
.k-card.hidden{display:none}
.know-cta{
  display:flex;flex-wrap:wrap;gap:16px;align-items:center;
  background:var(--card);border:1px solid var(--line);border-radius:24px;padding:16px;
  box-shadow:var(--shadow);margin:0 0 22px;
}
.know-cta img{width:160px;height:100px;object-fit:cover;border-radius:14px}
.know-cta h2{margin:0 0 6px;font-size:1.2rem;color:#f3f4f6}
.know-cta p{margin:0 0 10px;color:var(--muted)}
@media (max-width:720px){
  .lesson, .lesson.reverse{grid-template-columns:1fr}
  .lesson.reverse .lesson-fig{order:0}
  .hero{padding:22px 16px;border-radius:22px}
  .card-img{height:120px}
  .speak-ctrl{flex:1 1 140px}
  .speak-ctrl select{max-width:none;width:100%}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .card, button{transition:none}
  .card:hover{transform:none}
}