:root {
  --dt-primary: #0284c7;
  --dt-primary-hover: #0369a1;
  --dt-bg-card: #ffffff;
  --dt-border: #e2e8f0;
  --dt-text-main: #0f172a;
  --dt-text-muted: #64748b;
  --dt-pill-bg: #f1f5f9;
  --dt-pill-hover: #e2e8f0;
  --dt-result-bg: #f8fafc;
}

.dt-tool-container {
  max-width: 900px;
  margin: 0 auto 3rem auto;
  font-family: inherit;
  color: var(--dt-text-main);
}

.dt-mode-nav {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.dt-mode-btn {
  flex: 1;
  background: var(--dt-pill-bg);
  border: 1px solid var(--dt-border);
  color: var(--dt-text-muted);
  border-radius: 10px;
  padding: 0.85rem 1rem;
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.15s ease;
}

.dt-mode-btn.dt-active {
  background: var(--dt-primary);
  color: #ffffff;
  border-color: var(--dt-primary);
}

.dt-editor-card {
  background: var(--dt-bg-card);
  border: 1px solid var(--dt-border);
  border-radius: 12px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.dt-presets-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 1.25rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--dt-border);
}

.dt-presets-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--dt-text-muted);
}

.dt-pill-btn {
  background: var(--dt-pill-bg);
  border: 1px solid var(--dt-border);
  color: var(--dt-text-main);
  border-radius: 9999px;
  padding: 0.25rem 0.65rem;
  font-size: 0.75rem;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.dt-pill-btn:hover {
  background: var(--dt-pill-hover);
  border-color: var(--dt-primary);
}

.dt-pill-btn.dt-active {
  background: var(--dt-primary);
  color: #ffffff;
  border-color: var(--dt-primary);
}

.dt-quiz-stage {
  padding: 0.5rem 0;
}

.dt-quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.dt-q-badge {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--dt-primary);
}

.dt-score-badge {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--dt-text-muted);
}

.dt-progress-bar {
  width: 100%;
  height: 6px;
  background: var(--dt-pill-bg);
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 1.25rem;
}

.dt-progress-fill {
  height: 100%;
  background: var(--dt-primary);
  transition: width 0.25s ease;
}

.dt-q-text {
  font-size: 1.15rem;
  font-weight: 800;
  margin: 0 0 1.25rem 0;
  color: var(--dt-text-main);
  line-height: 1.4;
}

.dt-options-list {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  margin-bottom: 1.25rem;
}

.dt-opt-btn {
  background: var(--dt-pill-bg);
  border: 1px solid var(--dt-border);
  border-radius: 8px;
  padding: 0.85rem 1rem;
  text-align: left;
  font-size: 0.92rem;
  color: var(--dt-text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.dt-opt-btn:hover:not(:disabled) {
  border-color: var(--dt-primary);
  background: var(--dt-pill-hover);
}

.dt-opt-letter {
  background: var(--dt-bg-card);
  border: 1px solid var(--dt-border);
  border-radius: 4px;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.78rem;
  flex-shrink: 0;
}

.dt-opt-btn.dt-correct {
  background: #dcfce7 !important;
  border-color: #22c55e !important;
  color: #14532d !important;
}

.dt-opt-btn.dt-wrong {
  background: #fee2e2 !important;
  border-color: #ef4444 !important;
  color: #7f1d1d !important;
}

.dt-feedback-box {
  border-radius: 8px;
  padding: 1rem;
  margin-bottom: 1.25rem;
  border: 1px solid var(--dt-border);
  background: var(--dt-pill-bg);
}

.dt-feedback-title {
  font-weight: 800;
  font-size: 0.95rem;
  margin-bottom: 0.25rem;
}

.dt-feedback-text {
  font-size: 0.88rem;
  color: var(--dt-text-main);
  margin: 0;
  line-height: 1.45;
}

.dt-action-row {
  display: flex;
  gap: 0.75rem;
}

.dt-primary-btn {
  flex: 2;
  background: var(--dt-primary);
  color: #ffffff;
  border: none;
  border-radius: 8px;
  padding: 0.85rem 1.5rem;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.15s ease;
}

.dt-primary-btn:hover {
  background: var(--dt-primary-hover);
}

.dt-secondary-btn {
  background: var(--dt-pill-bg);
  color: var(--dt-text-main);
  border: 1px solid var(--dt-border);
  border-radius: 8px;
  padding: 0.85rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
}

/* Stopping Distance Section */
.dt-form-heading {
  font-size: 0.95rem;
  font-weight: 800;
  margin: 0 0 1.25rem 0;
  color: var(--dt-primary);
}

.dt-grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

@media (max-width: 600px) {
  .dt-grid-2 {
    grid-template-columns: 1fr;
  }
}

.dt-field label {
  display: block;
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
  color: var(--dt-text-main);
}

.dt-field select {
  width: 100%;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--dt-border);
  border-radius: 8px;
  background: var(--dt-bg-card);
  color: var(--dt-text-main);
  font-size: 0.95rem;
}

.dt-field input[type="range"] {
  width: 100%;
  margin-top: 0.6rem;
  cursor: pointer;
}

.dt-specs-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 1.25rem;
}

@media (max-width: 640px) {
  .dt-specs-grid {
    grid-template-columns: 1fr;
  }
}

.dt-spec-item {
  background: var(--dt-bg-card);
  border: 1px solid var(--dt-border);
  border-radius: 8px;
  padding: 1.15rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.dt-spec-name {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--dt-text-muted);
}

.dt-spec-val {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--dt-text-main);
}

.dt-spec-sub {
  font-size: 0.75rem;
  color: var(--dt-text-muted);
}

.dt-visual-track {
  display: flex;
  height: 28px;
  border-radius: 6px;
  overflow: hidden;
  font-size: 0.75rem;
  font-weight: 700;
  color: #ffffff;
  text-align: center;
  line-height: 28px;
}

.dt-bar-think {
  background: #0284c7;
}

.dt-bar-brake {
  background: #dc2626;
}

.dt-results-card {
  background: var(--dt-result-bg);
  border: 1px solid var(--dt-border);
  border-radius: 12px;
  padding: 1.75rem;
}

.dt-tip-box {
  background: var(--dt-bg-card);
  border: 1px solid var(--dt-border);
  border-radius: 8px;
  padding: 1.25rem;
}

.dt-tip-title {
  font-size: 0.9rem;
  font-weight: 700;
  margin: 0 0 0.25rem 0;
  color: var(--dt-primary);
}

.dt-tip-box p {
  margin: 0;
  font-size: 0.85rem;
  color: var(--dt-text-muted);
  line-height: 1.5;
}

.dt-dist-results {
  margin-top: 1rem;
}
.dt-topic-btn {
  font-family: inherit;
}

.dt-ad {
  overflow: hidden;
  min-height: 280px;
}
/* tf:dark-palette — generated by migrate_chrome.py */
/* Neutrals inherit the shared chrome tokens so all tools share one
   ground; brand hues are kept and lightened, never inverted. */
[data-theme="dark"] {
  --dt-primary: #81bcda;
  --dt-primary-hover: #69aed4;
  --dt-bg-card: var(--tf-surface);
  --dt-border: var(--tf-surface);
  --dt-text-main: var(--tf-ink);
  --dt-text-muted: var(--tf-ink-faint);
  --dt-pill-bg: var(--tf-surface);
  --dt-pill-hover: var(--tf-surface);
  --dt-result-bg: var(--tf-surface);
}