/* Mobile-first base styles for the app */
:root {
  --bg: #0b132b;
  --card: #1c2541;
  --text: #f8f9fb;
  --muted: #c7d3ed;
  --accent: #5bc0be;
  --danger: #ff6b6b;
  --success: #38d39f;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0; font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: var(--bg); color: var(--text);
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: 920px; margin: 0 auto; padding: 12px; }
.header { display:flex; align-items:center; justify-content:space-between; padding: 12px; background: var(--card); position: sticky; top:0; z-index:10; }
.logo { font-weight: 700; }
.streak { font-variant-numeric: tabular-nums; }
.nav a { margin-left: 12px; }

.card { background: var(--card); padding: 12px; border-radius: 10px; box-shadow: 0 3px 10px rgba(0,0,0,0.2); margin-bottom: 12px; }
.btn { display:inline-block; background: var(--accent); color: #041018; padding: 10px 14px; border-radius: 8px; font-weight: 600; border: none; cursor: pointer; }
.btn.secondary { background: #a3bffa; color: #051937; }
.btn.danger { background: var(--danger); color: #1a0e0e; }
.btn.success { background: var(--success); color: #052619; }
.btn:disabled { opacity: .7; cursor: not-allowed; }

form label { display:block; margin: 8px 0 4px; }
input, select, textarea { width: 100%; padding: 10px; border-radius: 8px; border: 1px solid #314165; background: #0f1b3e; color: var(--text); }
input[type="checkbox"], input[type="radio"] { width: auto; }

.list { list-style: none; margin:0; padding:0; }
.list li { padding: 10px; border-bottom: 1px solid #2b3758; }
.list li:last-child { border-bottom: none; }

.grid { display: grid; grid-template-columns: 1fr; gap: 12px; }
@media (min-width: 640px) { .grid.two { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 920px) { .grid.three { grid-template-columns: repeat(3, 1fr); } }

.question { padding: 10px; border-left: 4px solid var(--accent); margin: 10px 0; }
.options { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.option { background:#12204a; padding: 10px; border-radius: 8px; border:1px solid #2f3b60; cursor:pointer; }
.option.correct { border-color: var(--success); }
.option.wrong { border-color: var(--danger); }

.toast { position: fixed; left: 50%; transform: translateX(-50%); bottom: 24px; background: #162447; color: var(--text); padding: 10px 16px; border-radius: 10px; box-shadow: 0 2px 10px rgba(0,0,0,.4); }

.sr-only { position: absolute !important; width:1px; height:1px; overflow:hidden; clip: rect(1px,1px,1px,1px); white-space: nowrap; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}