:root {
  --ink: #12222b;
  --paper: #f6f4ee;
  --panel: #ffffff;
  --line: #d9d3c4;
  --teal: #0f5e5a;
  --teal-dark: #0a3f3c;
  --amber: #b5732a;
  --red: #a33c3c;
  --green: #2f7a4f;
  --muted: #6b6558;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: 'Georgia', 'Iowan Old Style', serif;
  -webkit-font-smoothing: antialiased;
}
.app { max-width: 900px; margin: 0 auto; padding: 20px 16px 60px; }

header.top {
  display: flex; justify-content: space-between; align-items: baseline;
  border-bottom: 2px solid var(--ink);
  padding-bottom: 12px; margin-bottom: 18px;
}
header.top h1 {
  font-size: 1.4rem; margin: 0; letter-spacing: 0.02em; font-weight: 700;
}
header.top .tag {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.12em;
  color: var(--muted);
}

.bar {
  display: flex; justify-content: space-between; align-items: center;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 0.85rem; margin-bottom: 14px; flex-wrap: wrap; gap: 10px;
}
.timer {
  background: var(--ink); color: var(--paper);
  padding: 6px 14px; border-radius: 3px; font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em; font-weight: 600;
}
.timer.warn { background: var(--red); }

.progress-track {
  height: 6px; background: var(--line); border-radius: 3px; overflow: hidden; margin-bottom: 18px;
}
.progress-fill { height: 100%; background: var(--teal); transition: width 0.2s; }

.section-nav {
  display: flex; gap: 6px; margin-bottom: 20px; flex-wrap: wrap;
  font-family: 'Helvetica Neue', Arial, sans-serif;
}
.section-nav button {
  flex: 1; min-width: 70px; padding: 8px 4px; border: 1px solid var(--line);
  background: var(--panel); color: var(--ink); font-size: 0.72rem; cursor: pointer;
  border-radius: 3px; font-weight: 600;
}
.section-nav button.active { background: var(--teal); color: #fff; border-color: var(--teal); }

.qgrid {
  display: grid; grid-template-columns: repeat(10, 1fr); gap: 5px; margin-bottom: 20px;
}
.qgrid button {
  aspect-ratio: 1; border: 1px solid var(--line); background: var(--panel);
  font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 0.68rem; cursor: pointer;
  border-radius: 3px; color: var(--muted);
}
.qgrid button.answered { background: var(--teal); color: #fff; border-color: var(--teal); }
.qgrid button.current { outline: 2px solid var(--amber); outline-offset: 1px; }

.card {
  background: var(--panel); border: 1px solid var(--line); border-radius: 6px;
  padding: 26px 24px; margin-bottom: 18px;
}
.qnum {
  font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 0.75rem;
  color: var(--teal); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 8px; font-weight: 700;
}
.qtext { font-size: 1.15rem; line-height: 1.5; margin-bottom: 20px; }
.qimg {
  display: block; max-width: 100%; max-height: 420px; margin: 0 0 20px;
  border: 1px solid var(--line); border-radius: 5px; background: #fff;
}
.review-item .qimg { max-height: 280px; margin-bottom: 10px; }

.opt {
  display: flex; align-items: flex-start; gap: 12px;
  padding: 12px 14px; border: 1px solid var(--line); border-radius: 5px;
  margin-bottom: 10px; cursor: pointer; transition: border-color 0.15s, background 0.15s;
  font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 0.95rem;
}
.opt:hover { border-color: var(--teal); }
.opt.selected { border-color: var(--teal); background: #eef6f4; }
.opt input { margin-top: 3px; accent-color: var(--teal); }
.opt .lab { font-weight: 700; color: var(--muted); margin-right: 4px; }

.navbtns {
  display: flex; justify-content: space-between; gap: 10px;
  font-family: 'Helvetica Neue', Arial, sans-serif;
}
.navbtns button {
  padding: 11px 20px; border-radius: 5px; border: 1px solid var(--ink);
  background: var(--panel); color: var(--ink); cursor: pointer; font-size: 0.9rem; font-weight: 600;
}
.navbtns button.primary { background: var(--ink); color: #fff; }
.navbtns button:disabled { opacity: 0.35; cursor: not-allowed; }

.clearbtn {
  font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 0.8rem;
  color: var(--muted); background: none; border: none; cursor: pointer; text-decoration: underline;
  margin-bottom: 14px; padding: 0;
}

.submit-row { text-align: center; margin-top: 24px; }
.submitbtn {
  font-family: 'Helvetica Neue', Arial, sans-serif; font-weight: 700; font-size: 1rem;
  padding: 14px 40px; background: var(--red); color: #fff; border: none;
  border-radius: 5px; cursor: pointer; letter-spacing: 0.02em;
}

/* Results screen */
.results h2 { font-size: 1.6rem; margin-bottom: 4px; }
.results .sub { font-family: 'Helvetica Neue', Arial, sans-serif; color: var(--muted); margin-bottom: 24px; }
.score-hero {
  background: var(--ink); color: var(--paper); border-radius: 8px;
  padding: 32px; text-align: center; margin-bottom: 24px;
}
.score-hero .num { font-size: 3.2rem; font-weight: 700; line-height: 1; }
.score-hero .den { font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 1rem; color: #b9c9c6; margin-top: 6px; }
.stat-row {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-bottom: 24px;
  font-family: 'Helvetica Neue', Arial, sans-serif; text-align: center;
}
.stat-row .stat { background: var(--panel); border: 1px solid var(--line); border-radius: 6px; padding: 14px 6px; }
.stat-row .stat .n { font-size: 1.4rem; font-weight: 700; }
.stat-row .stat .l { font-size: 0.7rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; margin-top: 2px; }
.stat-row .stat.correct .n { color: var(--green); }
.stat-row .stat.wrong .n { color: var(--red); }
.stat-row .stat.skip .n { color: var(--muted); }

table.secbreak {
  width: 100%; border-collapse: collapse; margin-bottom: 24px;
  font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 0.85rem;
}
table.secbreak th, table.secbreak td {
  border: 1px solid var(--line); padding: 8px 10px; text-align: center;
}
table.secbreak th { background: var(--panel); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--muted); }

.review-item {
  border: 1px solid var(--line); border-radius: 6px; padding: 16px 18px; margin-bottom: 10px;
  background: var(--panel);
}
.review-item.wrong { border-left: 4px solid var(--red); }
.review-item.correct { border-left: 4px solid var(--green); }
.review-item.skip { border-left: 4px solid var(--muted); }
.review-item .qtext { font-size: 1rem; margin-bottom: 10px; }
.review-item .rowline { font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 0.85rem; margin: 3px 0; }
.review-item .rowline.your { color: var(--red); }
.review-item .rowline.correctans { color: var(--green); }

.filter-row {
  display: flex; gap: 8px; margin-bottom: 16px; font-family: 'Helvetica Neue', Arial, sans-serif;
}
.filter-row button {
  padding: 7px 14px; border: 1px solid var(--line); background: var(--panel);
  border-radius: 4px; cursor: pointer; font-size: 0.8rem; font-weight: 600;
}
.filter-row button.active { background: var(--ink); color: #fff; border-color: var(--ink); }

.restart-row { text-align: center; margin-top: 20px; }
.restart-row button {
  font-family: 'Helvetica Neue', Arial, sans-serif; font-weight: 700;
  padding: 12px 28px; background: var(--teal); color: #fff; border: none;
  border-radius: 5px; cursor: pointer;
}

.intro {
  background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 30px 26px;
}
.intro h2 { margin-top: 0; }
.intro ul { font-family: 'Helvetica Neue', Arial, sans-serif; line-height: 1.8; font-size: 0.95rem; }
.intro .startbtn {
  font-family: 'Helvetica Neue', Arial, sans-serif; font-weight: 700; font-size: 1rem;
  padding: 13px 32px; background: var(--ink); color: #fff; border: none;
  border-radius: 5px; cursor: pointer; margin-top: 10px;
}
.intro .loading { font-family: 'Helvetica Neue', Arial, sans-serif; color: var(--muted); }
.intro .errbox { font-family: 'Helvetica Neue', Arial, sans-serif; color: var(--red); }

@media (max-width: 600px) {
  .qgrid { grid-template-columns: repeat(6, 1fr); }
  .stat-row { grid-template-columns: repeat(2, 1fr); }
  .qtext { font-size: 1.02rem; }
}