:root{
  --bg:#0d1117;
  --panel:#161b22;
  --panel2:#1c2230;
  --line:#2a3242;
  --text:#e6edf3;
  --muted:#9aa7b6;
  --accent:#ff9900;     /* AWS orange */
  --accent2:#ffb84d;
  --ok:#2ea043;
  --ng:#e5534b;
  --blue:#4493f8;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  background:radial-gradient(1200px 600px at 50% -10%, #182338 0%, var(--bg) 60%);
  color:var(--text);
  font-family:"Segoe UI",-apple-system,BlinkMacSystemFont,"Hiragino Kaku Gothic ProN","Yu Gothic",Meiryo,sans-serif;
  min-height:100vh;
  line-height:1.6;
}
.wrap{max-width:680px;margin:0 auto;padding:24px 16px 48px}
.head{text-align:center;margin-bottom:18px}
.head h1{margin:0;font-size:1.7rem;letter-spacing:.02em}
.tagline{color:var(--muted);margin:.4em 0 0;font-size:.95rem}

.view{animation:fadeIn .35s ease}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

.card{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:16px;
  padding:20px;
  box-shadow:0 8px 30px rgba(0,0,0,.35);
}
.lead{margin:0 0 12px;font-weight:600}

.cats{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-bottom:16px}
.cat-btn{
  display:flex;flex-direction:column;gap:2px;align-items:flex-start;
  background:var(--panel2);border:1px solid var(--line);color:var(--text);
  border-radius:12px;padding:12px 14px;cursor:pointer;text-align:left;
  transition:transform .12s ease,border-color .12s ease,background .12s ease;
}
.cat-btn:hover{transform:translateY(-2px);border-color:var(--accent);background:#222a39}
.cat-btn .cat-emoji{font-size:1.4rem}
.cat-btn .cat-name{font-weight:600}
.cat-btn .cat-n{font-size:.78rem;color:var(--muted)}

.opts{display:flex;flex-wrap:wrap;gap:14px;align-items:center;margin:4px 0 14px}
.opt{display:flex;align-items:center;gap:8px;font-size:.9rem;color:var(--muted)}
.opt select{
  background:var(--panel2);color:var(--text);border:1px solid var(--line);
  border-radius:8px;padding:6px 10px;font:inherit;
}
.opt-check{cursor:pointer}
.opt-check input{width:18px;height:18px;accent-color:var(--accent)}

.best{margin:8px 0 0;border-top:1px solid var(--line);padding-top:12px}
.best dt{font-size:.82rem;color:var(--muted);margin-bottom:6px}
.best dd{margin:0;font-size:.9rem}
.best-row{display:flex;justify-content:space-between;padding:3px 0;border-bottom:1px dashed var(--line)}
.best-row:last-child{border-bottom:0}
.best-row .br-rate{color:var(--accent2);font-variant-numeric:tabular-nums}

.rule{margin-top:14px;color:var(--muted);font-size:.88rem}
.rule summary{cursor:pointer;color:var(--accent2)}
.rule ul{margin:.6em 0 0;padding-left:1.2em}

/* buttons */
button{font:inherit}
.primary{
  background:linear-gradient(180deg,var(--accent2),var(--accent));
  color:#1a1200;border:0;border-radius:10px;padding:11px 18px;font-weight:700;
  cursor:pointer;transition:filter .12s ease,transform .12s ease;
}
.primary:hover{filter:brightness(1.06);transform:translateY(-1px)}
.ghost{
  background:transparent;color:var(--muted);border:1px solid var(--line);
  border-radius:10px;padding:10px 16px;cursor:pointer;transition:color .12s,border-color .12s;
}
.ghost:hover{color:var(--text);border-color:var(--accent)}
#btn-review{display:block;width:100%;margin:0 0 14px}

/* quiz */
.hud{display:flex;align-items:center;gap:12px;margin-bottom:10px}
.progress{font-weight:700;font-variant-numeric:tabular-nums}
.stat{margin-left:auto;display:flex;align-items:baseline;gap:6px}
.stat-label{font-size:.78rem;color:var(--muted)}
.stat-val{font-weight:700;color:var(--accent2);font-variant-numeric:tabular-nums}
.hud .ghost{padding:6px 12px}

.qbar{height:6px;background:var(--panel2);border-radius:99px;overflow:hidden;margin-bottom:14px}
.qbar-fill{height:100%;width:0;background:linear-gradient(90deg,var(--accent),var(--accent2));transition:width .3s ease}

.quiz-card{min-height:240px}
.q-cat{display:inline-block;font-size:.76rem;color:var(--accent2);background:#2a2110;
  border:1px solid #4a3a10;border-radius:99px;padding:2px 10px;margin:0 0 10px}
.q-text{font-size:1.15rem;margin:0 0 16px;line-height:1.5}

.choices{display:flex;flex-direction:column;gap:10px}
.choice{
  display:flex;gap:10px;align-items:flex-start;text-align:left;
  background:var(--panel2);border:1px solid var(--line);color:var(--text);
  border-radius:10px;padding:12px 14px;cursor:pointer;width:100%;
  transition:border-color .12s,background .12s,transform .1s;
}
.choice:hover:not(:disabled){border-color:var(--blue);transform:translateY(-1px)}
.choice:disabled{cursor:default}
.choice .ckey{
  flex:0 0 auto;width:24px;height:24px;border-radius:6px;background:#0e1420;
  display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.85rem;color:var(--muted)
}
.choice.correct{border-color:var(--ok);background:rgba(46,160,67,.14)}
.choice.correct .ckey{background:var(--ok);color:#04210b}
.choice.wrong{border-color:var(--ng);background:rgba(229,83,75,.14)}
.choice.wrong .ckey{background:var(--ng);color:#2a0606}

.explain{margin-top:16px;border-top:1px solid var(--line);padding-top:14px;animation:fadeIn .3s ease}
.verdict{font-weight:800;margin:0 0 6px}
.verdict.ok{color:var(--ok)}
.verdict.ng{color:var(--ng)}
.explain-text{color:var(--muted);font-size:.92rem;margin:0 0 14px}

/* result */
.result-title{margin:0 0 8px;text-align:center}
.result-score{text-align:center;font-size:1.5rem;font-weight:800;margin:0 0 4px}
.result-rate{text-align:center;font-size:1.05rem;color:var(--accent2);margin:0 0 8px}
.result-best{text-align:center;color:var(--muted);font-size:.9rem;margin:0 0 16px;min-height:1.2em}
.actions{display:flex;flex-direction:column;gap:10px}
.actions button{width:100%}

.foot{text-align:center;color:var(--muted);font-size:.78rem;margin-top:22px}

@media (max-width:420px){
  .cats{grid-template-columns:1fr}
}
@media (prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important}
}