:root{
  --bg:#f6f8fb; --card:#fff; --border:#e5e7ef; --ok:#1b873f; --bad:#b3261e; --ink:#111;
}
*{box-sizing:border-box}
body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,Arial;color:var(--ink);background:var(--bg);line-height:1.45}
header{background:#0d1b2a;color:#fff;padding:18px}
header h1{margin:0 0 6px;font-size:22px}
header p{margin:0;color:#e6eef7;font-size:14px}
.container{max-width:900px;margin:20px auto 40px;padding:0 16px}
.card{background:var(--card);border:1px solid var(--border);border-radius:14px;padding:16px;margin-bottom:14px}
.flex{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.btn{border:1px solid var(--border);background:#fff;padding:10px 14px;border-radius:10px;cursor:pointer;font-weight:600}
.btn.primary{background:#0b5ed7;border-color:#0b5ed7;color:#fff}
.btn.ghost{background:transparent}
.q{font-weight:700;margin-bottom:8px}
.opt{display:flex;gap:10px;align-items:flex-start;padding:8px;border-radius:10px;border:1px solid transparent}
.opt:hover{background:#f7f9ff}
.opt.correct{background:#ecfff2;border-color:#c8f0d4}
.opt.incorrect{background:#fff1f0;border-color:#ffd7d4}
.score{font-weight:700}
footer{text-align:center;color:#777;padding:30px 10px;font-size:13px}