:root {
  --bg: #f6f7f9; --card: #ffffff; --ink: #1c2330; --muted: #5b6573; --line: #d9dee6;
  --accent: #1f5fbf; --accent-ink: #ffffff; --ok: #1e8e4a; --bad: #c8322b; --warn: #c98a12;
  --flag: #e0a800; --soft: #eef2f8;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12161c; --card: #1a2029; --ink: #e8ecf1; --muted: #9aa5b4; --line: #2c3541;
    --accent: #5b9cff; --accent-ink: #0b1220; --ok: #43c26e; --bad: #ff6b61; --warn: #f0b642;
    --flag: #f2c14e; --soft: #222a35;
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg); color: var(--ink);
  font: 17px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
a { color: var(--accent); }
.wrap { max-width: 860px; margin: 0 auto; padding: 16px; }
header.top {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 10px 16px; border-bottom: 1px solid var(--line); background: var(--card);
  position: sticky; top: 0; z-index: 5;
}
header.top .brand { font-weight: 700; text-decoration: none; color: var(--ink); }
header.top .brand small { color: var(--muted); font-weight: 400; margin-left: 6px; }
h1 { font-size: 1.6rem; margin: 18px 0 8px; }
h2 { font-size: 1.2rem; margin: 22px 0 8px; }
p.lead { color: var(--muted); margin-top: 0; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: 18px; margin: 14px 0;
}
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 12px; }
.test-tile {
  display: block; text-decoration: none; color: inherit; background: var(--card);
  border: 1px solid var(--line); border-radius: 12px; padding: 14px;
}
.test-tile:hover { border-color: var(--accent); }
.test-tile .t { font-weight: 700; font-size: 1.05rem; }
.test-tile .s { color: var(--muted); font-size: 0.9rem; margin-top: 4px; }
.test-tile .score { margin-top: 8px; font-size: 0.9rem; }
.pill {
  display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 0.8rem;
  background: var(--soft); color: var(--ink); border: 1px solid var(--line);
}
.pill.nocalc { background: #fff3cd; color: #5c4400; border-color: #ffe08a; }
.pill.calc { background: #e3f2e8; color: #14502b; border-color: #b7dfc6; }
@media (prefers-color-scheme: dark) {
  .pill.nocalc { background: #4a3a05; color: #ffe08a; border-color: #6b5410; }
  .pill.calc { background: #163d26; color: #b7dfc6; border-color: #24603b; }
}
button, .btn {
  font: inherit; cursor: pointer; border-radius: 10px; padding: 10px 16px;
  border: 1px solid var(--line); background: var(--card); color: var(--ink);
  text-decoration: none; display: inline-block;
}
button.primary, .btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); font-weight: 600; }
button.danger { border-color: var(--bad); color: var(--bad); }
button:disabled { opacity: 0.45; cursor: default; }
.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.spread { justify-content: space-between; }

/* runner */
.runner-bar {
  display: flex; align-items: center; justify-content: space-between; gap: 10px;
  padding: 8px 0; flex-wrap: wrap;
}
.timer { font-variant-numeric: tabular-nums; font-weight: 700; font-size: 1.1rem; }
.timer.low { color: var(--bad); }
.qnum { font-weight: 700; }
.stem { font-size: 1.08rem; }
.stem table, .stem-table { border-collapse: collapse; margin: 10px 0; }
.stem td, .stem th { border: 1px solid var(--line); padding: 4px 10px; text-align: center; }
.stem svg { max-width: 100%; height: auto; display: block; margin: 10px 0; background: #fff; border-radius: 6px; }
.choices { list-style: none; padding: 0; margin: 14px 0 0; }
.choices li { margin: 8px 0; }
.choices label {
  display: flex; gap: 12px; align-items: flex-start; padding: 12px 14px;
  border: 1px solid var(--line); border-radius: 10px; cursor: pointer; background: var(--card);
}
.choices label:hover { border-color: var(--accent); }
.choices input { margin-top: 5px; }
.choices label.sel { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent) inset; }
.choices label.correct { border-color: var(--ok); box-shadow: 0 0 0 2px var(--ok) inset; }
.choices label.wrong { border-color: var(--bad); box-shadow: 0 0 0 2px var(--bad) inset; }
.letter { font-weight: 700; min-width: 1.4em; }
.numeric input {
  font: inherit; font-size: 1.15rem; padding: 10px 12px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--card); color: var(--ink); width: 220px; max-width: 100%;
}
.numeric .hint { color: var(--muted); font-size: 0.9rem; margin-top: 6px; }
.palette { display: grid; grid-template-columns: repeat(auto-fill, minmax(40px, 1fr)); gap: 6px; margin-top: 10px; }
.palette button {
  padding: 6px 0; font-size: 0.9rem; border-radius: 8px; position: relative;
}
.palette button.answered { background: var(--soft); border-color: var(--accent); }
.palette button.current { outline: 2px solid var(--accent); }
.palette button.flagged::after {
  content: ""; position: absolute; top: 3px; right: 3px; width: 8px; height: 8px;
  border-radius: 50%; background: var(--flag);
}
.palette button.right { background: var(--ok); color: #fff; border-color: var(--ok); }
.palette button.wrong { background: var(--bad); color: #fff; border-color: var(--bad); }
.palette button.blank { background: var(--card); color: var(--muted); }
.flagbtn.on { background: var(--flag); color: #221a00; border-color: var(--flag); }
.result-big { font-size: 2.4rem; font-weight: 800; }
.verdict { font-size: 1.1rem; margin-top: 4px; }
.verdict.pass { color: var(--ok); } .verdict.fail { color: var(--bad); }
.topic-table { width: 100%; border-collapse: collapse; margin-top: 10px; }
.topic-table td, .topic-table th { padding: 6px 8px; border-bottom: 1px solid var(--line); text-align: left; }
.topic-table td:last-child, .topic-table th:last-child { text-align: right; }
.expl { background: var(--soft); border-radius: 10px; padding: 12px 14px; margin-top: 12px; }
.expl .lbl { font-weight: 700; margin-bottom: 4px; }
.status { color: var(--muted); font-size: 0.9rem; }
.muted { color: var(--muted); }
.warnbox { border-left: 4px solid var(--warn); padding: 8px 12px; background: var(--soft); border-radius: 8px; margin: 10px 0; }
footer { color: var(--muted); font-size: 0.85rem; text-align: center; padding: 30px 0 16px; }
@media (max-width: 600px) {
  body { font-size: 16px; }
  .wrap { padding: 12px; }
  .card { padding: 14px; }
  .palette { grid-template-columns: repeat(8, 1fr); }
}
@media print {
  header.top, .noprint { display: none !important; }
  body { background: #fff; color: #000; font-size: 12pt; }
  .card { border: none; padding: 0; margin: 0 0 14px; break-inside: avoid; }
  .stem svg { background: #fff; }
  .choices label { border: none; padding: 2px 0; }
  .pagebreak { break-before: page; }
}

.passage { background: var(--card); border: 1px solid var(--line); border-left: 4px solid var(--accent); border-radius: 12px; padding: 14px 18px; margin: 14px 0; font-size: 1rem; line-height: 1.55; }
.passage .ptitle { font-weight: 700; margin-bottom: 6px; }
.passage p { margin: 8px 0; }
.passage .lnum { color: var(--muted); font-size: 0.8rem; margin-right: 6px; }
.stem blockquote, .passage blockquote { margin: 8px 0 8px 12px; padding-left: 10px; border-left: 3px solid var(--line); color: var(--ink); }
.palette button.answered.blank { background: var(--card); }
@media print { .passage { break-inside: avoid; } }