:root{
  --ink:#1f2937;
  --ink-soft:#6b7280;
  --line:#e5e7eb;
  --card:#ffffff;
  --radius:20px;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0}
body{
  font-family:"Noto Sans Thai",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  color:var(--ink);
  background:
    radial-gradient(1200px 600px at 80% 110%, #ffe3e3 0%, rgba(255,227,227,0) 60%),
    radial-gradient(900px 500px at 10% -10%, #fff1e6 0%, rgba(255,241,230,0) 60%),
    #fdf8f6;
  min-height:100vh;
}
.screen{display:none;max-width:1240px;margin:0 auto;padding:28px 20px 60px}
.screen.active{display:block}

/* ---------- หน้าแรก ---------- */
.hero{text-align:center;padding:26px 0 30px}
.hero h1{margin:0;font-size:34px;font-weight:700;letter-spacing:-.5px}
.hero-sub{margin:8px 0 0;color:var(--ink-soft);font-size:16px}
.hero-stats{margin-top:18px;display:flex;gap:10px;justify-content:center;flex-wrap:wrap}
.chip{
  background:#fff;border:1px solid var(--line);border-radius:999px;
  padding:7px 16px;font-size:14px;color:var(--ink-soft);
  box-shadow:0 1px 2px rgba(17,24,39,.04);
}
.chip b{color:var(--ink);font-weight:600}

.grid{
  display:grid;gap:22px;
  grid-template-columns:repeat(auto-fill,minmax(215px,1fr));
}
.card{
  position:relative;background:var(--card);border:1px solid transparent;
  border-radius:var(--radius);padding:30px 22px 24px;text-align:center;
  cursor:pointer;overflow:hidden;
  box-shadow:0 1px 2px rgba(17,24,39,.05),0 8px 24px -12px rgba(17,24,39,.14);
  transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease;
}
.card::before{
  content:"";position:absolute;top:0;left:0;right:0;height:5px;background:var(--c);
}
.card:hover{
  transform:translateY(-4px);
  border-color:var(--c);
  box-shadow:0 1px 2px rgba(17,24,39,.05),0 18px 34px -16px rgba(17,24,39,.28);
}
.card:active{transform:translateY(-1px)}
.card-icon{height:56px;display:flex;align-items:center;justify-content:center;margin-bottom:14px}
.card-icon svg{width:44px;height:44px;stroke:var(--c);fill:none;stroke-width:1.8;
  stroke-linecap:round;stroke-linejoin:round}
.card h3{margin:0 0 8px;font-size:19px;font-weight:700;line-height:1.35}
.card p{margin:0;color:#9aa3af;font-size:14px;line-height:1.55;min-height:44px}
.card-meta{
  display:flex;gap:16px;justify-content:center;align-items:center;
  margin:16px 0 12px;font-size:14px;color:var(--ink-soft);
}
.card-meta span{display:inline-flex;align-items:center;gap:5px}
.card-meta svg{width:16px;height:16px;stroke:#9aa3af;fill:none;stroke-width:1.7;
  stroke-linecap:round;stroke-linejoin:round}
.bar{height:7px;border-radius:999px;background:#eef0f2;overflow:hidden}
.bar i{display:block;height:100%;border-radius:999px;background:var(--c);
  transition:width .5s cubic-bezier(.4,0,.2,1)}

.foot{text-align:center;margin-top:38px}

/* ---------- ปุ่ม ---------- */
.btn-primary,.btn-ghost,.btn-next{
  font-family:inherit;font-size:16px;font-weight:600;cursor:pointer;
  border-radius:14px;padding:13px 26px;border:1px solid transparent;transition:all .15s ease;
}
.btn-primary{background:var(--c,#0ea5e9);color:#fff}
.btn-primary:hover{filter:brightness(1.07)}
.btn-ghost{background:#fff;color:var(--ink-soft);border-color:var(--line)}
.btn-ghost:hover{color:var(--ink);border-color:#cbd5e1}
.icon-btn{
  width:42px;height:42px;flex:none;border-radius:12px;border:1px solid var(--line);
  background:#fff;font-size:20px;line-height:1;cursor:pointer;color:var(--ink);
}
.icon-btn:hover{border-color:#cbd5e1}

/* ---------- หน้าทำข้อสอบ ---------- */
.quiz-bar{display:flex;align-items:center;gap:14px;max-width:760px;margin:0 auto 22px}
.quiz-bar-mid{flex:1;min-width:0}
.quiz-subject{font-weight:700;font-size:16px;margin-bottom:7px}
.quiz-progress{height:7px;border-radius:999px;background:#eef0f2;overflow:hidden}
.quiz-progress span{display:block;height:100%;background:var(--c);border-radius:999px;
  transition:width .3s ease}
.quiz-count{font-size:15px;color:var(--ink-soft);font-variant-numeric:tabular-nums;flex:none}

.quiz-body{max-width:760px;margin:0 auto}
.q-card{
  background:#fff;border-radius:24px;padding:30px 28px;
  box-shadow:0 1px 2px rgba(17,24,39,.05),0 10px 30px -14px rgba(17,24,39,.18);
}
.q-topic{
  display:inline-block;font-size:13px;font-weight:600;color:var(--c);
  background:#f4f6f8;background:color-mix(in srgb,var(--c) 12%,#fff);
  padding:5px 12px;border-radius:999px;margin-bottom:14px;
}
.q-text{margin:0 0 22px;font-size:22px;font-weight:600;line-height:1.6}
.choices{display:flex;flex-direction:column;gap:11px}
.choice{
  display:flex;align-items:flex-start;gap:13px;text-align:left;width:100%;
  font-family:inherit;font-size:17px;line-height:1.55;color:var(--ink);
  background:#fff;border:1.5px solid var(--line);border-radius:15px;
  padding:15px 17px;cursor:pointer;transition:all .15s ease;
}
.choice:hover:not(:disabled){border-color:var(--c);background:#fcfdff}
.choice:disabled{cursor:default}
.choice b{
  flex:none;width:27px;height:27px;border-radius:9px;background:#f3f4f6;
  display:grid;place-items:center;font-size:14px;font-weight:700;color:var(--ink-soft);
}
.choice.correct{border-color:#22c55e;background:#f0fdf4}
.choice.correct b{background:#22c55e;color:#fff}
.choice.wrong{border-color:#ef4444;background:#fef2f2}
.choice.wrong b{background:#ef4444;color:#fff}
.explain{
  display:none;margin-top:18px;padding:15px 17px;border-radius:14px;
  background:#f8fafc;border-left:4px solid var(--c);
  font-size:15.5px;line-height:1.65;color:#475569;
}
.explain.show{display:block}
.explain b{color:var(--ink)}
.btn-next{
  display:none;width:100%;margin-top:18px;background:var(--c);color:#fff;
}
.btn-next.show{display:block}
.btn-next:hover{filter:brightness(1.07)}

/* ---------- หน้าสรุป ---------- */
.result-card{
  max-width:660px;margin:24px auto 0;background:#fff;border-radius:24px;
  padding:40px 30px;text-align:center;
  box-shadow:0 1px 2px rgba(17,24,39,.05),0 10px 30px -14px rgba(17,24,39,.18);
}
.result-emoji{font-size:60px;line-height:1}
.result-card h2{margin:14px 0 4px;font-size:26px}
.result-score{margin:16px 0 6px;font-size:56px;font-weight:700;color:var(--c);
  font-variant-numeric:tabular-nums}
.result-score small{font-size:24px;color:#9aa3af;font-weight:600}
.result-msg{color:var(--ink-soft);font-size:16px;margin:6px 0 26px}
.result-btns{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.review{margin-top:34px;text-align:left;border-top:1px solid var(--line);padding-top:24px}
.review h4{margin:0 0 14px;font-size:16px;color:var(--ink-soft);font-weight:600}
.rv{padding:13px 0;border-bottom:1px dashed var(--line);font-size:15.5px;line-height:1.6}
.rv:last-child{border-bottom:0}
.rv-q{font-weight:600;margin-bottom:5px}
.rv-a{color:#dc2626;font-size:14.5px}
.rv-a.ok{color:#16a34a}
.rv-right{color:#16a34a;font-size:14.5px}

@media(max-width:600px){
  .screen{padding:18px 14px 50px}
  .hero h1{font-size:26px}
  .grid{grid-template-columns:repeat(auto-fill,minmax(155px,1fr));gap:14px}
  .card{padding:22px 14px 18px;border-radius:16px}
  .card h3{font-size:16px}
  .card p{font-size:12.5px;min-height:38px}
  .card-meta{font-size:12.5px;gap:11px}
  .q-card{padding:22px 18px;border-radius:18px}
  .q-text{font-size:19px}
  .choice{font-size:16px;padding:13px 14px}
  .result-score{font-size:46px}
}