:root {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --ink: #1d232b;
  --muted: #5b6573;
  --line: #dde2e8;
  --accent: #1f5fbf;
  --accent-ink: #ffffff;
  --sel: #e7efff;
  --err: #b42318;
}
* { box-sizing: border-box; }
html, body { margin: 0; background: var(--bg); color: var(--ink);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
.topbar { position: sticky; top: 0; z-index: 10; display: flex; align-items: center; gap: 24px;
  padding: 10px 24px; background: var(--panel); border-bottom: 1px solid var(--line); }
.brand { font-weight: 700; }
.progress { flex: 1; display: flex; align-items: center; gap: 12px; max-width: 520px; }
.progress .bar { height: 8px; background: var(--accent); border-radius: 4px; transition: width .2s; }
.progress { position: relative; }
.progress::before { content: ""; position: absolute; left: 0; right: 90px; height: 8px; background: var(--line); border-radius: 4px; z-index: -1; }
#progress-text { margin-left: auto; color: var(--muted); font-size: 14px; white-space: nowrap; }
main { max-width: 1280px; margin: 0 auto; padding: 24px 16px 200px; }
.panel { background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 28px 32px; max-width: 900px; margin: 0 auto; }
h1 { font-size: 26px; margin: 0 0 12px; } h2 { font-size: 21px; margin: 0 0 12px; }
.facts li { margin: 4px 0; }
.small { font-size: 14px; color: var(--muted); }
.check { display: flex; gap: 10px; align-items: flex-start; margin: 16px 0; cursor: pointer; }
.actions { display: flex; gap: 12px; margin-top: 20px; }
button { font: inherit; padding: 9px 22px; border-radius: 8px; border: 1px solid var(--accent); background: var(--accent); color: var(--accent-ink); cursor: pointer; }
button:disabled { opacity: .45; cursor: not-allowed; }
button.secondary { background: var(--panel); color: var(--accent); }
fieldset { border: 1px solid var(--line); border-radius: 8px; margin: 0 0 16px; padding: 12px 16px; }
legend { font-weight: 600; padding: 0 6px; }
fieldset label { display: block; margin: 4px 0; cursor: pointer; }
textarea { width: 100%; font: inherit; padding: 10px; border: 1px solid var(--line); border-radius: 8px; }
.tutorial-grid { display: grid; grid-template-columns: 260px 1fr; gap: 24px; align-items: start; }
.tutorial-grid img { width: 260px; height: 260px; object-fit: contain; border-radius: 6px; border: 1px solid var(--line); }
figure { margin: 0; } figcaption { font-size: 13px; color: var(--muted); margin-top: 4px; }
.card-figure { margin-top: 16px; } .card-figure img { width: 100%; height: auto; border: 1px solid var(--line); border-radius: 6px; }
.item-head { display: grid; grid-template-columns: 300px 1fr; gap: 24px; background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 16px 20px; }
.test-figure img { width: 300px; height: 300px; object-fit: contain; border-radius: 6px; border: 1px solid var(--line); }
.card-block { background: var(--panel); border: 1px solid var(--line); border-radius: 10px; margin-top: 14px; padding: 10px 14px; }
.card-label { font-weight: 700; font-size: 18px; margin: 0 0 6px; }
.card-block img { width: 100%; height: auto; display: block; }
.questions { position: fixed; left: 0; right: 0; bottom: 0; z-index: 20; background: var(--panel); border-top: 2px solid var(--line);
  padding: 10px 24px; display: grid; gap: 6px; box-shadow: 0 -4px 14px rgba(0,0,0,.06); }
.q { display: flex; align-items: center; gap: 16px; max-width: 1280px; margin: 0 auto; width: 100%; }
.q-text { flex: 1; }
.q-opts { display: flex; gap: 8px; }
.q-opts button { min-width: 52px; padding: 5px 14px; background: var(--panel); color: var(--ink); border: 1px solid var(--line); }
.q-opts button.selected { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.q-opts button.tie { min-width: 92px; color: var(--muted); }
.q-opts button.tie.selected { color: var(--accent-ink); }
.banner { max-width: 900px; margin: 0 auto 16px; padding: 10px 14px; border: 1px solid var(--err); border-radius: 8px; background: #fff5f4; }
.q-foot { display: flex; align-items: center; gap: 16px; max-width: 1280px; margin: 4px auto 0; width: 100%; }
.q-foot .check { margin: 0; flex: 1; }
.error { color: var(--err); font-size: 14px; }
@media (max-width: 760px) {
  .tutorial-grid, .item-head { grid-template-columns: 1fr; }
  .test-figure img, .tutorial-grid img { width: 100%; height: auto; }
  .q { flex-direction: column; align-items: flex-start; gap: 4px; }
  .panel { padding: 20px 16px; }
}