:root {
  --bg: #fafaf7;
  --fg: #1f2328;
  --muted: #6b7280;
  --card: #ffffff;
  --border: #e5e7eb;
  --accent: #0e7490;
  --right: #15803d;
  --wrong: #b91c1c;
  --code: #f3f4f6;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111418;
    --fg: #e6e6e6;
    --muted: #9ca3af;
    --card: #1a1f25;
    --border: #2d333b;
    --accent: #22d3ee;
    --right: #4ade80;
    --wrong: #f87171;
    --code: #22272e;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.6 system-ui, sans-serif;
}

header {
  display: flex;
  gap: 1.5rem;
  align-items: baseline;
  padding: 0.8rem 1.2rem;
  border-bottom: 1px solid var(--border);
}

header .brand { font-weight: 700; font-size: 1.2rem; }
header .logout { margin-left: auto; }
button.link {
  padding: 0;
  background: none;
  color: var(--accent);
  font-weight: normal;
  text-decoration: underline;
}

.login { max-width: 22rem; margin: 3rem auto; }
.login label { display: block; margin-top: 0.8rem; font-weight: 600; }
.login input[type="password"] {
  display: block;
  width: 100%;
  margin: 0.3rem 0 1rem;
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  background: var(--bg);
  color: var(--fg);
  font: inherit;
}

main { max-width: 46rem; margin: 0 auto; padding: 1rem 1.2rem 4rem; }

a { color: var(--accent); }

.meta, .crumbs, .hint { color: var(--muted); font-size: 0.9rem; }

.notes { list-style: none; padding: 0; }
.notes li {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem 1rem;
  align-items: center;
  padding: 0.8rem 0;
  border-bottom: 1px solid var(--border);
}
.notes li > a:first-child { font-weight: 600; flex: 1 1 100%; }
.notes .meta { flex: 1; }

.button, button {
  display: inline-block;
  padding: 0.55rem 1.1rem;
  border: 0;
  border-radius: 0.5rem;
  background: var(--accent);
  color: var(--bg);
  font: inherit;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
}
.button.secondary { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
.button.small { padding: 0.25rem 0.8rem; font-size: 0.9rem; }

.actions { display: flex; gap: 0.8rem; flex-wrap: wrap; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 0.8rem;
  padding: 1.2rem 1.4rem;
  margin: 1rem 0;
}
.card h2 { margin-top: 0.2rem; font-size: 1.25rem; }
.result { text-align: center; }
.result .actions { justify-content: center; }
.big { font-size: 1.4rem; font-weight: 600; }

.options { border: 0; padding: 0; margin: 0 0 1rem; list-style: none; }
.options label, .options li {
  display: block;
  padding: 0.6rem 0.8rem;
  margin: 0.4rem 0;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
}
.options label { cursor: pointer; }
.options label:has(input:checked) { border-color: var(--accent); }
.options input { margin-right: 0.4rem; }
.letter { font-weight: 600; color: var(--muted); }
.solved .right { border-color: var(--right); color: var(--right); font-weight: 600; }
.solved .wrong { border-color: var(--wrong); color: var(--wrong); text-decoration: line-through; }

.verdict { font-weight: 700; margin-bottom: 0; }
.verdict.right { color: var(--right); }
.verdict.wrong { color: var(--wrong); }

details.hint { margin-bottom: 1rem; }

.audio {
  margin: 1rem 0;
  padding: 0.8rem 1rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 0.8rem;
}
.audio figcaption { font-weight: 600; margin-bottom: 0.4rem; }
.audio audio { width: 100%; }

.note pre, .note code { background: var(--code); border-radius: 0.3rem; font-size: 0.9em; }
.note code { padding: 0.1em 0.3em; }
.note pre { padding: 0.8rem 1rem; overflow-x: auto; }
.note pre code { padding: 0; background: none; }
.note table { border-collapse: collapse; display: block; overflow-x: auto; }
.note th, .note td { border: 1px solid var(--border); padding: 0.3rem 0.6rem; text-align: left; }