:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #666666;
  --border: #dddddd;
  --card-bg: #f7f7f8;
  --accent: #2563eb;
  --accent-fg: #ffffff;
  --correct: #15803d;
  --correct-bg: #dcfce7;
  --incorrect: #b91c1c;
  --incorrect-bg: #fee2e2;
  --link: #2563eb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14151a;
    --fg: #e6e6e6;
    --muted: #9a9a9a;
    --border: #33343a;
    --card-bg: #1c1d23;
    --accent: #5b8def;
    --accent-fg: #0b0c0f;
    --correct: #4ade80;
    --correct-bg: #123a22;
    --incorrect: #f87171;
    --incorrect-bg: #3a1414;
    --link: #7fa8f0;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.5;
}

.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--fg);
  text-decoration: none;
}

.header-status {
  font-size: 0.85rem;
  color: var(--muted);
  text-decoration: none;
}

.header-status:hover {
  color: var(--link);
}

#app-root {
  max-width: 900px;
  margin: 0 auto;
  padding: 1.5rem;
}

.app-footer {
  max-width: 900px;
  margin: 2rem auto;
  padding: 0 1.5rem 2rem;
  color: var(--muted);
  font-size: 0.85rem;
}

.app-footer code {
  background: var(--card-bg);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
}

h2 {
  margin-top: 0;
}

.intro {
  color: var(--muted);
}

.cert-section {
  margin-bottom: 2rem;
}

.domain-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 0.5rem;
}

.domain-table td,
.domain-table th {
  border-bottom: 1px solid var(--border);
  padding: 0.6rem 0.5rem;
  text-align: left;
  vertical-align: middle;
}

.domain-table th {
  color: var(--muted);
  font-weight: 600;
  font-size: 0.85rem;
}

.domain-table--fullmock {
  margin-top: 1rem;
}

.weight {
  color: var(--muted);
  font-size: 0.8rem;
}

.actions {
  white-space: nowrap;
}

.attempt-summary {
  color: var(--muted);
  font-size: 0.85rem;
  margin-left: 0.5rem;
}

.attempt-summary--none {
  opacity: 0.6;
}

.btn {
  font: inherit;
  padding: 0.45rem 0.9rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--card-bg);
  color: var(--fg);
  cursor: pointer;
}

.btn:hover {
  filter: brightness(0.95);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn--primary {
  background: var(--accent);
  color: var(--accent-fg);
  border-color: var(--accent);
}

.btn--small {
  padding: 0.3rem 0.6rem;
  font-size: 0.85rem;
}

.btn--link {
  background: none;
  border: none;
  color: var(--link);
  text-decoration: underline;
}

.btn--ok {
  background: var(--correct-bg);
  color: var(--correct);
  border-color: var(--correct);
}

.btn--miss {
  background: var(--incorrect-bg);
  color: var(--incorrect);
  border-color: var(--incorrect);
}

.badge {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
}

.badge--pass {
  background: var(--correct-bg);
  color: var(--correct);
}

.badge--fail {
  background: var(--incorrect-bg);
  color: var(--incorrect);
}

.runner-progress {
  display: flex;
  gap: 1rem;
  align-items: center;
  color: var(--muted);
  font-size: 0.9rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.runner-progress > span:first-child {
  color: var(--fg);
  font-weight: 600;
  flex: 1;
}

.timer {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
}

.timer--up {
  color: var(--incorrect);
}

.tags {
  margin-bottom: 0.5rem;
}

.tag {
  display: inline-block;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.1rem 0.45rem;
  font-size: 0.75rem;
  margin-right: 0.35rem;
  color: var(--muted);
}

.stem {
  margin: 0 0 1rem;
  font-size: 1.1rem;
}

.hint {
  color: var(--muted);
  font-size: 0.85rem;
  margin-top: -0.5rem;
}

.options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.option {
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  background: var(--card-bg);
}

.option input {
  margin-top: 0.2rem;
}

.option--selected {
  border-color: var(--accent);
}

.option--correct {
  border-color: var(--correct);
  background: var(--correct-bg);
  color: var(--correct);
}

.option--incorrect {
  border-color: var(--incorrect);
  background: var(--incorrect-bg);
  color: var(--incorrect);
}

.option-letter {
  font-weight: 700;
}

.feedback {
  border-radius: 8px;
  padding: 0.75rem 1rem;
  margin-bottom: 1rem;
}

.feedback--correct {
  background: var(--correct-bg);
  color: var(--correct);
}

.feedback--incorrect {
  background: var(--incorrect-bg);
  color: var(--incorrect);
}

.feedback--reveal {
  background: var(--card-bg);
  color: var(--fg);
  border: 1px solid var(--border);
}

.explanation {
  margin: 0.4rem 0 0;
  color: var(--fg);
  opacity: 0.9;
}

.citation {
  margin: 0.4rem 0 0;
  font-size: 0.8rem;
  font-style: italic;
  color: var(--muted);
}

.runner-actions {
  display: flex;
  gap: 0.6rem;
}

.score-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.75rem;
}

.breakdown-table {
  width: 100%;
  border-collapse: collapse;
  margin: 0.5rem 0 1.5rem;
}

.breakdown-table td,
.breakdown-table th {
  border-bottom: 1px solid var(--border);
  padding: 0.4rem 0.5rem;
  text-align: left;
}

.review-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.review-item {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  background: var(--card-bg);
}

.review-correct {
  font-weight: 600;
  margin: 0.3rem 0;
}