:root {
  --bg: #f4f6fa;
  --card: #ffffff;
  --ink: #1b2430;
  --muted: #64748b;
  --line: #e2e8f0;
  --primary: #2563eb;
  --primary-ink: #ffffff;
  --ok: #15803d;
  --ok-bg: #e8f6ec;
  --bad: #c62828;
  --bad-bg: #fdecec;
  --warn: #b45309;
  --info-bg: #e8f0fe;
  --radius: 12px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f141b; --card: #171e28; --ink: #e5eaf1; --muted: #93a1b3; --line: #2a3442;
    --primary: #4f8bff; --ok: #4ade80; --ok-bg: #12301d; --bad: #f87171; --bad-bg: #3a1717; --info-bg: #1b2a44;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 15px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
a { color: var(--primary); }
.top { background: var(--card); border-bottom: 1px solid var(--line); padding: 12px 16px; }
.brand { font-weight: 700; text-decoration: none; color: var(--ink); }
.wrap { max-width: 1120px; margin: 0 auto; padding: 16px; display: flex; flex-direction: column; gap: 16px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
h1 { font-size: 1.5rem; margin: 0 0 4px; }
h2 { font-size: 1.1rem; margin: 0 0 12px; }
h3 { font-size: .95rem; margin: 0 0 10px; }
.muted { color: var(--muted); }

/* start */
.start { display: grid; gap: 16px; margin-top: 16px; max-width: 560px; }
.field { display: grid; gap: 6px; border: 0; padding: 0; margin: 0; }
.field > span, legend { font-weight: 600; }
input[name=name], select { font: inherit; padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--card); color: var(--ink); }
.choice { display: flex; gap: 10px; align-items: flex-start; padding: 12px; border: 1px solid var(--line); border-radius: 10px; cursor: pointer; margin-top: 6px; }
.choice:has(input:checked) { border-color: var(--primary); background: var(--info-bg); }
.choice small { display: block; color: var(--muted); }
.checks { display: flex; flex-wrap: wrap; gap: 16px; }
.btn { font: inherit; display: inline-flex; align-items: center; justify-content: center; gap: 6px; padding: 9px 16px; border-radius: 8px; border: 1px solid var(--line); background: var(--card); color: var(--ink); cursor: pointer; text-decoration: none; }
.btn:hover:not(:disabled) { border-color: var(--primary); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn.primary { background: var(--primary); border-color: var(--primary); color: var(--primary-ink); font-weight: 600; }
.btn.block { width: 100%; }
.row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.row form { margin: 0; }

/* table */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: .92rem; }
th, td { padding: 8px 10px; border-bottom: 1px solid var(--line); text-align: left; white-space: nowrap; }
th { color: var(--muted); font-weight: 600; font-size: .8rem; text-transform: uppercase; letter-spacing: .03em; }
.num { text-align: right; }
.badge { display: inline-block; padding: 1px 8px; border-radius: 999px; font-size: .78rem; font-weight: 600; }
.badge.ok { background: var(--ok-bg); color: var(--ok); }
.badge.bad { background: var(--bad-bg); color: var(--bad); }
.badge.info { background: var(--info-bg); color: var(--primary); }

/* exam */
.exam { display: flex; flex-direction: column; gap: 16px; }
.exam-bar { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; padding: 12px 16px; position: sticky; top: 8px; z-index: 5; }
.exam-bar-right { display: flex; gap: 14px; align-items: center; }
.timer { font-weight: 700; font-variant-numeric: tabular-nums; }
.timer.low { color: var(--bad); }
.exam-body { display: grid; grid-template-columns: 1fr 260px; gap: 16px; align-items: start; }
@media (max-width: 860px) { .exam-body { grid-template-columns: 1fr; } }
.nav { position: sticky; top: 76px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(36px, 1fr)); gap: 6px; }
.cell { font: inherit; font-size: .82rem; height: 34px; border-radius: 6px; border: 1px solid var(--line); background: var(--card); color: var(--ink); cursor: pointer; }
.cell.answered { background: var(--info-bg); border-color: var(--primary); }
.cell.right { background: var(--ok-bg); border-color: var(--ok); }
.cell.wrong { background: var(--bad-bg); border-color: var(--bad); }
.cell.flagged { box-shadow: inset 0 -3px 0 var(--warn); }
.cell.current { outline: 2px solid var(--primary); outline-offset: 1px; font-weight: 700; }
.legend { font-size: .78rem; color: var(--muted); display: flex; gap: 6px; align-items: center; flex-wrap: wrap; margin: 12px 0; }
.dot { width: 10px; height: 10px; border-radius: 3px; border: 1px solid var(--line); display: inline-block; }
.dot.answered { background: var(--info-bg); border-color: var(--primary); }
.dot.flagged { box-shadow: inset 0 -3px 0 var(--warn); }

.question { display: flex; flex-direction: column; gap: 14px; }
.q-head { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.q-no { font-weight: 700; }
.flag { margin-left: auto; font: inherit; font-size: .85rem; background: none; border: 1px solid var(--line); border-radius: 999px; padding: 2px 10px; color: var(--muted); cursor: pointer; }
.flag.on { color: var(--warn); border-color: var(--warn); }
.prompt { font-size: 1.05rem; margin: 0; white-space: pre-line; }
.exhibit { margin: 0; border: 1px solid var(--line); border-radius: 10px; padding: 10px; background: var(--bg); }
.exhibit figcaption { font-size: .75rem; font-weight: 700; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; margin-bottom: 6px; }
.exhibit img { display: block; max-width: 100%; height: auto; border-radius: 6px; background: #fff; }
.exhibit pre { margin: 0; white-space: pre-wrap; font-size: .88rem; }
.options { display: grid; gap: 8px; }
.option { display: flex; gap: 10px; align-items: flex-start; padding: 11px 12px; border: 1px solid var(--line); border-radius: 10px; cursor: pointer; }
label.option:hover { border-color: var(--primary); }
.option input { margin-top: 4px; }
.option.picked { border-color: var(--primary); background: var(--info-bg); }
.option.right { border-color: var(--ok); background: var(--ok-bg); }
.option.wrong { border-color: var(--bad); background: var(--bad-bg); }
.letter { font-weight: 700; min-width: 1.1em; }
.mine { margin-left: auto; font-size: .75rem; color: var(--muted); white-space: nowrap; }
.verdict { margin: 0; padding: 10px 12px; border-radius: 8px; font-weight: 600; }
.verdict.ok { background: var(--ok-bg); color: var(--ok); }
.verdict.bad { background: var(--bad-bg); color: var(--bad); }
.q-actions { display: flex; gap: 8px; justify-content: space-between; flex-wrap: wrap; }

/* result */
.result { display: flex; gap: 24px; align-items: center; flex-wrap: wrap; }
.score { width: 140px; height: 140px; border-radius: 50%; display: flex; flex-direction: column; align-items: center; justify-content: center; border: 8px solid; flex-shrink: 0; }
.score.ok { border-color: var(--ok); color: var(--ok); }
.score.bad { border-color: var(--bad); color: var(--bad); }
.score-value { font-size: 2rem; font-weight: 800; }
.score-label { font-size: .75rem; font-weight: 700; letter-spacing: .05em; }
.result-info { flex: 1; min-width: 240px; }
.review { display: flex; flex-direction: column; gap: 12px; }
.question.is-right { border-left: 4px solid var(--ok); }
.question.is-wrong { border-left: 4px solid var(--bad); }