:root {
  --bg: #0f172a; --card: #1e293b; --line: #334155;
  --fg: #e2e8f0; --dim: #94a3b8;
  --accent: #38bdf8; --ok: #4ade80; --bad: #f87171; --warn: #fbbf24;
  --r: 14px;
}
@media (prefers-color-scheme: light) {
  :root { --bg:#f8fafc; --card:#fff; --line:#e2e8f0; --fg:#0f172a; --dim:#64748b; --accent:#0284c7; }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Pretendard", system-ui, sans-serif;
  padding: max(12px, env(safe-area-inset-top)) 16px calc(24px + env(safe-area-inset-bottom));
  max-width: 720px; margin-inline: auto;
  overflow-wrap: break-word;
}

header { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 18px; }
header h1 { font-size: 15px; font-weight: 600; margin: 0; color: var(--dim); letter-spacing: -.01em; }
#crumb { font-size: 13px; color: var(--dim); margin-left: auto; }

h2 { font-size: 17px; margin: 0 0 10px; letter-spacing: -.01em; }
p { margin: 0 0 10px; }
.stack > * + * { margin-top: 14px; }
.muted { color: var(--dim); }
.small { font-size: 13px; line-height: 1.6; }
.row { display: flex; gap: 8px; flex-wrap: wrap; }
.row > button { flex: 1; min-width: 130px; }

.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 16px; }

button {
  font: inherit; font-weight: 600; border-radius: 10px; padding: 12px 16px;
  border: 1px solid var(--line); background: transparent; color: var(--fg);
  cursor: pointer; touch-action: manipulation; transition: opacity .15s;
}
button:active { opacity: .6; }
.primary { background: var(--accent); border-color: var(--accent); color: #06121f; width: 100%; }
.danger  { background: var(--bad); border-color: var(--bad); color: #1a0606; }
.ghost   { background: transparent; }
button[hidden] { display: none; }
.sticky { position: sticky; bottom: 12px; }

textarea {
  width: 100%; font: inherit; line-height: 1.6; padding: 12px; margin: 10px 0 0;
  background: var(--bg); color: var(--fg);
  border: 1px solid var(--line); border-radius: 10px; resize: vertical;
}
textarea:focus { outline: 2px solid var(--accent); outline-offset: -1px; }

.timer { font-variant-numeric: tabular-nums; font-size: 28px; font-weight: 700; text-align: center; letter-spacing: -.02em; }
.timer.big { font-size: 44px; }
.timer small { font-size: 13px; font-weight: 400; color: var(--dim); }
.timer.over { color: var(--warn); }

.tabs { display: flex; gap: 6px; }
.tabs button { flex: 1; padding: 9px; font-size: 14px; }
.tabs .on { background: var(--accent); border-color: var(--accent); color: #06121f; }

.prose { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 18px; }
.prose h1 { font-size: 20px; margin: 0 0 12px; }
.prose h2 { font-size: 17px; margin: 22px 0 8px; padding-top: 14px; border-top: 1px solid var(--line); }
.prose h2:first-of-type { border-top: 0; padding-top: 0; }
.prose h3 { font-size: 15px; margin: 16px 0 6px; }
.prose ul { padding-left: 20px; margin: 8px 0; }
.prose li { margin: 4px 0; }
.prose blockquote { margin: 10px 0; padding: 8px 14px; border-left: 3px solid var(--accent); color: var(--dim); }
.prose code { background: var(--bg); padding: 1px 5px; border-radius: 5px; font-size: .9em; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 20px 0; }
.prose table { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 14px; display: block; overflow-x: auto; }
.prose th, .prose td { border: 1px solid var(--line); padding: 7px 9px; text-align: left; }
.prose th { background: var(--bg); }

.q { font-size: 17px; font-weight: 600; line-height: 1.55; }
.verdict .row { margin-top: 10px; }
[data-choices] label {
  display: block; padding: 12px; margin: 6px 0;
  border: 1px solid var(--line); border-radius: 10px; cursor: pointer;
}
[data-choices] input { margin-right: 9px; }

.gaps, .cov { list-style: none; padding: 0; margin: 0; }
.gaps li, .cov li { padding: 9px 0; border-top: 1px solid var(--line); font-size: 14px; }
.gaps li:first-child, .cov li:first-child { border-top: 0; }
.tag { font-size: 11px; padding: 2px 7px; border-radius: 999px; border: 1px solid var(--line); color: var(--dim); margin-left: 6px; white-space: nowrap; }
.hit::before { content: "✅ "; }
.miss::before { content: "❌ "; }
.bar { height: 7px; background: var(--line); border-radius: 4px; overflow: hidden; margin: 6px 0 2px; }
.bar > i { display: block; height: 100%; background: var(--accent); }

.probe { border-top: 1px solid var(--line); padding-top: 12px; margin-top: 12px; }
.probe:first-child { border-top: 0; padding-top: 0; margin-top: 0; }