:root {
  --cobalt: #1d4ed8;
  --cobalt-dark: #1e3a8a;
  --orange: #ea580c;
  --teal: #0d9488;
  --ink: #0f172a;
  --muted: #475569;
  --bg: #f8fafc;
  --card: #fff;
  --focus: #f59e0b;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, Segoe UI, Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.5;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--focus);
  color: var(--ink);
  padding: 0.5rem 1rem;
  z-index: 9;
}
.skip-link:focus { left: 0; }

.masthead {
  background: var(--cobalt-dark);
  color: #fff;
  padding: 1rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  justify-content: space-between;
}

.brand { display: flex; gap: 0.75rem; align-items: center; }
.logo {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 0.5rem;
  background: linear-gradient(135deg, var(--orange), var(--teal));
  display: grid;
  place-items: center;
  font-weight: 700;
}
.brand-name { margin: 0; font-weight: 700; }
.brand-tag { margin: 0; opacity: 0.9; font-size: 0.9rem; }
.banner.warn { background: #fef3c7; color: #78350f; padding: 0.5rem 0.75rem; border-radius: 0.5rem; }

.layout { max-width: 56rem; margin: 0 auto; padding: 1rem 1.25rem 2rem; }

.card {
  background: var(--card);
  border: 1px solid #cbd5e1;
  border-radius: 0.75rem;
  padding: 1rem 1.25rem;
  margin-bottom: 1rem;
}

h1 { font-size: 1.35rem; margin-top: 0; }
h2 { font-size: 1.1rem; margin-top: 0; color: var(--cobalt-dark); }
.muted { color: var(--muted); font-size: 0.95rem; }
.score { font-weight: 600; color: #9a3412; }

.contrast-banner { border-left: 5px solid var(--orange); }
.contrast-row { margin: 0.35rem 0; }
.pill {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  margin-right: 0.35rem;
}
.pill-warn { background: #ffedd5; color: #9a3412; }
.pill-ok { background: #ccfbf1; color: #115e59; }

.split-diagrams {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 0.75rem;
}
@media (max-width: 520px) {
  .split-diagrams { grid-template-columns: 1fr; }
}
.diagram-title { font-size: 0.85rem; font-weight: 600; margin: 0 0 0.35rem; }
.participant-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.35rem;
}
.cell {
  text-align: center;
  padding: 0.45rem 0.25rem;
  border-radius: 0.35rem;
  font-weight: 700;
  font-size: 0.85rem;
}
.cell-train { background: #ccfbf1; color: #115e59; border: 2px solid var(--teal); }
.cell-test { background: #ffedd5; color: #9a3412; border: 2px solid var(--orange); }

.split-row { border-top: 4px solid var(--orange); }
.split-person { border-top: 4px solid var(--teal); }

.split-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
@media (max-width: 640px) {
  .split-grid { grid-template-columns: 1fr; }
}

table { width: 100%; border-collapse: collapse; font-size: 0.95rem; }
th, td { border-bottom: 1px solid #e2e8f0; padding: 0.4rem 0.35rem; text-align: left; }
.id-chip {
  display: inline-block;
  min-width: 1.5rem;
  font-weight: 700;
  color: var(--cobalt);
}
.set-train { color: #115e59; font-weight: 600; }
.set-test { color: #9a3412; font-weight: 600; }
.set-icon { font-family: monospace; margin-right: 0.25rem; }

.id-summary { list-style: none; padding: 0; margin: 0.75rem 0 0; font-size: 0.92rem; }
.id-summary li { margin-bottom: 0.35rem; }

.question { border: 0; padding: 0; margin: 1.25rem 0; }
.choice { display: block; margin: 0.35rem 0; cursor: pointer; }
.choice input:disabled + * { opacity: 1; }
.choice input:disabled { cursor: not-allowed; }
.status { font-size: 0.9rem; color: var(--muted); }
.retry { margin-top: 0.75rem; padding-top: 0.75rem; border-top: 1px dashed #cbd5e1; }

#journalList { padding-left: 1.1rem; }
#journalList .empty { list-style: none; margin-left: -1.1rem; color: var(--muted); }

blockquote {
  margin: 0.75rem 0;
  padding: 0.75rem 1rem;
  border-left: 4px solid var(--cobalt);
  background: #eff6ff;
}

.btn-secondary {
  background: #fff;
  border: 2px solid var(--cobalt);
  color: var(--cobalt-dark);
  padding: 0.5rem 1rem;
  border-radius: 0.5rem;
  font-weight: 600;
  cursor: pointer;
}
.btn-secondary:hover { background: #eff6ff; }

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.practice label { margin-right: 1rem; }