:root {
  --bg: #f6f7f9; --fg: #1d2430; --muted: #5b6575; --card: #ffffff; --line: #d9dee6; --acc: #1f4e79; --acc2: #e7eef6;
  --good: #1e7b45; --bad: #b3261e; --mid: #a86b00; --r: 10px;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #14181f; --fg: #e6e9ee; --muted: #9aa4b2; --card: #1d232c; --line: #323b48; --acc: #7fb0e0; --acc2: #22303f; --good: #5cc28a; --bad: #f08a80; --mid: #e0b35c; }
}
* { box-sizing: border-box; }
html, body { margin: 0; background: var(--bg); color: var(--fg); font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
.wrap { max-width: 860px; margin: 0 auto; padding: 0 16px 24px; }
h1 { font-size: 1.25rem; margin: 0; flex: 1; }
h2 { font-size: 1.05rem; margin: 18px 0 8px; }
button, select, textarea, input { font: inherit; color: inherit; }
button { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 10px 14px; cursor: pointer; min-height: 44px; }
button:focus-visible, select:focus-visible, input:focus-visible, textarea:focus-visible { outline: 3px solid var(--acc); outline-offset: 2px; }
button[disabled] { opacity: .5; cursor: default; }
button.primary { background: var(--acc); color: #fff; border-color: var(--acc); font-weight: 600; }
@media (prefers-color-scheme: dark) { button.primary { color: #0d1622; } }
button.link { border: 0; background: none; color: var(--acc); padding: 6px 8px; min-height: 36px; }
button.link.on { font-weight: 700; }
button.on, .pill.on { background: var(--acc2); border-color: var(--acc); font-weight: 600; }
select, textarea { width: 100%; padding: 10px; border: 1px solid var(--line); border-radius: var(--r); background: var(--card); }
.muted { color: var(--muted); }
.warn { color: var(--bad); font-weight: 600; }
.good { color: var(--good); } .bad { color: var(--bad); } .mid { color: var(--mid); }
.top { display: flex; align-items: center; gap: 8px; padding: 14px 0 10px; border-bottom: 1px solid var(--line); margin-bottom: 12px; }
.top.home { flex-direction: column; align-items: flex-start; }
.top.home h1 { font-size: 1.8rem; color: var(--acc); }
.sub { margin: 0; color: var(--muted); }
.langs { display: flex; gap: 6px; margin-top: 8px; }
.fb { min-height: 36px; padding: 4px 10px; }
.cards { display: grid; gap: 12px; }
.card { text-align: left; display: flex; flex-direction: column; gap: 4px; padding: 16px; }
.card strong { font-size: 1.1rem; color: var(--acc); }
.card.small { padding: 10px 16px; }
.note { font-size: .9rem; }
.form label { display: block; margin: 10px 0; }
.row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 10px 0; }
.pill { min-width: 44px; }
.cluster { border: 1px solid var(--line); border-radius: var(--r); margin: 8px 0; padding: 6px 12px 10px; background: var(--card); }
.cluster legend { font-weight: 600; padding: 0 6px; }
.chk { display: grid !important; grid-template-columns: 28px 1fr; align-items: start; margin: 6px 0 !important; cursor: pointer; }
.chk input { width: 20px; height: 20px; margin-top: 3px; }
.chk small { grid-column: 2; color: var(--muted); }
.chk.inline { display: inline-grid !important; margin-right: 14px !important; }
.tests { display: flex; flex-wrap: wrap; }
.summary { background: var(--acc2); border-radius: var(--r); padding: 10px 14px; margin: 14px 0; }
.summary p { margin: 2px 0; }
.bar { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 8px; font-size: .9rem; color: var(--muted); margin-bottom: 8px; }
.clock { font-variant-numeric: tabular-nums; font-weight: 700; color: var(--fg); background: var(--acc2); padding: 2px 10px; border-radius: 999px; }
.item { display: grid; gap: 12px; }
.stim, .q { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 12px 14px; }
.stim h2 { margin-top: 0; }
.stim p { margin: 0 0 8px; }
.docs .tabs { display: flex; gap: 6px; overflow-x: auto; padding-bottom: 6px; border-bottom: 1px solid var(--line); }
.docs .tabs button { white-space: nowrap; min-height: 38px; padding: 6px 10px; font-size: .9rem; }
.doc { max-height: 46vh; overflow: auto; padding-top: 8px; }
.mail { border-left: 3px solid var(--acc); padding-left: 10px; }
.tbl { border-collapse: collapse; width: 100%; margin: 6px 0 10px; font-size: .95rem; }
.tbl th, .tbl td { border: 1px solid var(--line); padding: 5px 8px; text-align: left; vertical-align: top; }
.tbl th { background: var(--acc2); }
.num { text-align: right !important; font-variant-numeric: tabular-nums; white-space: nowrap; }
.react { font-size: 1.05rem; }
.scale { display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; }
.rate { display: flex; flex-direction: column; align-items: center; padding: 8px 2px; }
.rate b { font-size: 1.15rem; }
.rate small { font-size: .72rem; color: var(--muted); text-align: center; line-height: 1.2; }
.opts { display: grid; gap: 8px; }
.opts.figs { grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); }
.opt { display: flex; gap: 10px; align-items: flex-start; text-align: left; }
.opt b { min-width: 1.2em; }
.svgwrap { display: block; max-width: 100%; overflow-x: auto; }
.svgwrap svg { max-width: 100%; height: auto; display: block; margin: 0 auto; }
.fig .svgwrap svg { background: #fff; border-radius: 6px; }
.opt .svgwrap svg { background: #fff; border-radius: 6px; }
.matrix { border-collapse: collapse; width: 100%; }
.matrix th, .matrix td { border: 1px solid var(--line); padding: 4px; text-align: center; font-size: .9rem; }
.matrix td:first-child { text-align: left; }
.cell { min-height: 36px; min-width: 36px; padding: 0; border: 0; background: none; font-size: 1.2rem; }
.fbk { border-radius: var(--r); padding: 8px 12px; margin-top: 10px; border: 1px solid var(--line); }
.fbk.good { border-color: var(--good); } .fbk.bad { border-color: var(--bad); }
.fbk p { margin: 4px 0; }
.nav { position: sticky; bottom: 0; display: flex; justify-content: space-between; gap: 8px; padding: 10px 0; background: var(--bg); border-top: 1px solid var(--line); margin-top: 12px; }
.center { text-align: center; padding: 30px 0; }
.intro ul { padding-left: 20px; }
.meter { height: 10px; background: var(--acc2); border-radius: 6px; overflow: hidden; min-width: 80px; }
.meter span { display: block; height: 100%; background: var(--acc); }
details.rev { border: 1px solid var(--line); border-radius: var(--r); padding: 6px 10px; margin: 6px 0; background: var(--card); }
details.rev.good summary { color: var(--good); } details.rev.bad summary { color: var(--bad); } details.rev.mid summary { color: var(--mid); }
.modal { position: fixed; inset: 0; background: rgba(0, 0, 0, .45); display: flex; align-items: center; justify-content: center; padding: 16px; z-index: 10; }
.modal .box { background: var(--card); border-radius: var(--r); padding: 16px; width: 100%; max-width: 520px; }
.foot { margin-top: 28px; padding-top: 10px; border-top: 1px solid var(--line); font-size: .85rem; color: var(--muted); }
@media (max-width: 700px) {
  /* keep the answer controls on screen: the stimulus scrolls on its own (LogiQ lesson: answer and next visible) */
  .item .stim { max-height: 30vh; overflow: auto; }
  .react { font-size: 1rem; }
  .q { padding: 10px 12px; }
  .item .stim.docs .doc { max-height: 30vh; }
  .item .stim.fig { max-height: 46vh; }
  .top.run h1 { font-size: 1.05rem; }
  .bar { margin-bottom: 4px; }
}
@media (max-width: 420px) {
  .wrap { padding: 0 10px 16px; }
  .rate small { font-size: .62rem; }
  .doc { max-height: 38vh; }
}
@media print { .nav, .fb, .bar button { display: none; } }