/* TDN exam surfaces — Khan Academy–inspired clean education UI.
   Scoped so other subjects keep the existing hand-drawn system. */

.subject-page--tdn,
.practice-shell[data-subject-id="thi-tran-dai-nghia"],
.practice-app:has(.practice-shell[data-subject-id="thi-tran-dai-nghia"]),
.tdn-mock-app,
.tdn-drill-app,
.tdn93-app,
.tdn-improvement-app {
  --tdn-bg: #f7f8fa;
  --tdn-surface: #ffffff;
  --tdn-ink: #21242c;
  --tdn-muted: #5f6368;
  --tdn-line: #e4e8ee;
  --tdn-line-strong: #d5dbe3;
  --tdn-blue: #1865f2;
  --tdn-blue-hover: #0f52d9;
  --tdn-blue-soft: #e8f0fe;
  --tdn-green: #0a8754;
  --tdn-green-soft: #e6f6ee;
  --tdn-amber: #c97800;
  --tdn-amber-soft: #fff6e5;
  --tdn-red: #d93025;
  --tdn-red-soft: #fdecea;
  --tdn-radius: 12px;
  --tdn-radius-lg: 16px;
  --tdn-shadow: 0 1px 2px rgba(33, 36, 44, 0.06);
  --tdn-shadow-raised: 0 8px 24px rgba(33, 36, 44, 0.08);
  --tdn-focus: 0 0 0 3px rgba(24, 101, 242, 0.22);
  color: var(--tdn-ink);
}

/* ------------------------------------------------------------------ */
/* Hub: subject page                                                   */
/* ------------------------------------------------------------------ */

.subject-page--tdn {
  display: grid;
  gap: 18px;
}

.subject-page--tdn .topbar {
  margin-bottom: 0;
}

.subject-page--tdn .subject-hero,
.subject-page--tdn .subject-hero--practice,
.subject-page--tdn .subject-hero--thi-tdn,
.subject-page--tdn .subject-hero--tdn-clean {
  margin: 0;
  padding: 22px 24px;
  min-height: 0;
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.subject-page--tdn .subject-hero--art::before,
.subject-page--tdn .subject-hero--art::after {
  display: none;
}

.subject-page--tdn .subject-hero-main {
  grid-template-columns: 52px minmax(0, 1fr) minmax(240px, 280px);
  gap: 18px;
  align-items: center;
}

.subject-page--tdn .subject-hero .icon-box,
.subject-page--tdn .subject-hero .icon-box.has-badge {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: var(--tdn-blue-soft);
  color: var(--tdn-blue);
  box-shadow: none;
}

.subject-page--tdn .subject-hero-badge {
  display: inline-flex;
  margin-bottom: 6px;
  padding: 3px 8px;
  border-radius: 999px;
  background: var(--tdn-blue-soft);
  color: var(--tdn-blue);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: none;
}

.subject-page--tdn .subject-hero-copy h1 {
  margin: 0 0 6px;
  color: var(--tdn-ink);
  font-size: clamp(24px, 3vw, 30px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.subject-page--tdn .subject-hero-copy .subtitle {
  max-width: 46rem;
  margin: 0;
  color: var(--tdn-muted);
  font-size: 15px;
  font-weight: 500;
  line-height: 1.55;
}

.subject-page--tdn .subject-hero-steps {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.subject-page--tdn .subject-hero-steps span {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 32px;
  padding: 0 10px 0 4px;
  border: 1px solid var(--tdn-line);
  border-radius: 999px;
  background: #fafbfc;
  color: var(--tdn-muted);
  font-size: 13px;
  font-weight: 600;
}

.subject-page--tdn .subject-hero-steps strong {
  display: grid;
  width: 22px;
  height: 22px;
  place-items: center;
  border-radius: 999px;
  background: var(--tdn-blue);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
}

.subject-page--tdn .subject-hero-stats {
  display: grid;
  gap: 10px;
  padding: 14px 16px;
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius);
  background: #fafbfc;
  box-shadow: none;
}

.subject-page--tdn .subject-hero-progress-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.subject-page--tdn .subject-hero-stats span {
  color: var(--tdn-muted);
  font-size: 12px;
  font-weight: 650;
}

.subject-page--tdn .subject-hero-stats strong {
  color: var(--tdn-ink);
  font-size: 16px;
  font-weight: 700;
}

.subject-page--tdn .progress-ring,
.subject-page--tdn .progress-ring-sm {
  color: var(--tdn-blue);
}

.subject-page--tdn .subject-start-button {
  grid-column: 1 / -1;
  min-height: 44px;
  border-radius: 10px;
  background: var(--tdn-blue);
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  box-shadow: none;
}

.subject-page--tdn .subject-start-button:hover,
.subject-page--tdn .subject-start-button:focus-visible {
  background: var(--tdn-blue-hover);
  transform: none;
  box-shadow: var(--tdn-focus);
}

.subject-page--tdn .button.primary {
  min-height: 44px;
  border-radius: 10px;
  background: var(--tdn-blue);
  color: #fff;
  font-weight: 700;
  box-shadow: none;
}

.subject-page--tdn .button.primary:hover,
.subject-page--tdn .button.primary:focus-visible {
  background: var(--tdn-blue-hover);
}

.subject-page--tdn .button:not(.primary):not(.danger) {
  min-height: 44px;
  border: 1px solid var(--tdn-line-strong);
  border-radius: 10px;
  background: var(--tdn-surface);
  color: var(--tdn-ink);
  font-weight: 650;
}

/* Readiness board */
.subject-page--tdn .tdn-90-section-board {
  gap: 16px;
  margin: 0;
  padding: 20px 22px;
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.subject-page--tdn .tdn-90-kicker {
  display: inline-block;
  margin-bottom: 4px;
  color: var(--tdn-blue);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.subject-page--tdn .tdn-90-section-board h3 {
  margin: 0;
  color: var(--tdn-ink);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.subject-page--tdn .tdn-90-section-board > p,
.subject-page--tdn .tdn-90-section-board .tdn-90-note {
  margin: 0;
  color: var(--tdn-muted);
  font-size: 14px;
  line-height: 1.55;
}

.subject-page--tdn .tdn-90-section-bars {
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.subject-page--tdn .tdn-90-section-bars li {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 6px 12px;
  align-items: center;
}

.subject-page--tdn .tdn-90-section-bars span {
  color: var(--tdn-ink);
  font-size: 14px;
  font-weight: 650;
}

.subject-page--tdn .tdn-90-section-bars b {
  color: var(--tdn-muted);
  font-size: 13px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.subject-page--tdn .tdn-90-bar {
  height: 8px;
  border-radius: 999px;
  background: #eef1f6;
}

.subject-page--tdn .tdn-90-bar i {
  background: var(--tdn-blue);
}

.subject-page--tdn .tdn-90-bar.is-low i {
  background: var(--tdn-amber);
}

.subject-page--tdn .tdn-90-actions {
  gap: 10px;
  margin-top: 4px;
}

/* Action pair: section drills + 93+ */
.subject-page--tdn .tdn-hub-practice {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
}

.subject-page--tdn .tdn-drill-home-cards {
  margin: 0;
}

.subject-page--tdn .tdn-drill-home-cards article,
.subject-page--tdn .tdn93-home-banner {
  height: 100%;
  margin: 0;
  padding: 18px 20px;
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.subject-page--tdn .tdn93-home-banner {
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 14px;
}

.subject-page--tdn .tdn93-home-banner > .button,
.subject-page--tdn .tdn-drill-home-cards .button {
  grid-column: 1 / -1;
  justify-self: start;
  margin-top: 6px;
}

.subject-page--tdn .tdn-drill-home-cards span,
.subject-page--tdn .tdn93-home-copy > span {
  color: var(--tdn-blue);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.01em;
  text-transform: none;
}

.subject-page--tdn .tdn-drill-home-cards h3,
.subject-page--tdn .tdn93-home-copy h3 {
  margin: 4px 0 6px;
  color: var(--tdn-ink);
  font-size: 17px;
  font-weight: 700;
}

.subject-page--tdn .tdn-drill-home-cards p,
.subject-page--tdn .tdn93-home-copy p {
  margin: 0;
  color: var(--tdn-muted);
  font-size: 14px;
  line-height: 1.5;
}

.subject-page--tdn .tdn93-home-mark {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: var(--tdn-blue);
  color: #fff;
  font-size: 16px;
  font-weight: 800;
}

.subject-page--tdn .tdn93-home-banner.is-ready {
  border-color: color-mix(in srgb, var(--tdn-green) 28%, var(--tdn-line));
  background: var(--tdn-surface);
}

.subject-page--tdn .tdn93-home-banner.is-ready .tdn93-home-mark {
  background: var(--tdn-green);
}

/* Saved items + AI */
.subject-page--tdn .subject-saved-panel,
.subject-page--tdn .tdn-ai-overview {
  margin: 0;
  padding: 18px 20px;
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.subject-page--tdn .tdn-ai-overview {
  border-radius: var(--tdn-radius-lg);
}

.subject-page--tdn .tdn-ai-mark {
  display: grid;
  width: 40px;
  height: 40px;
  place-items: center;
  border-radius: 10px;
  background: var(--tdn-blue-soft);
  color: var(--tdn-blue);
  font-size: 18px;
}

.subject-page--tdn .tdn-ai-overview .section-eyebrow {
  color: var(--tdn-blue);
  font-size: 12px;
  font-weight: 700;
  text-transform: none;
  letter-spacing: 0;
}

.subject-page--tdn .tdn-ai-overview h2 {
  margin: 2px 0 6px;
  color: var(--tdn-ink);
  font-size: 17px;
  font-weight: 700;
}

.subject-page--tdn .tdn-ai-overview p {
  margin: 0;
  color: var(--tdn-muted);
  font-size: 14px;
}

/* Year-set catalog */
.subject-page--tdn .detail-layout,
.subject-page--tdn .tdn-set-accordion-layout {
  margin: 0;
}

.subject-page--tdn .detail-panel {
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
  overflow: hidden;
}

.subject-page--tdn .tdn-set-accordion-layout .detail-panel-header {
  padding: 20px 22px 8px;
}

.subject-page--tdn .mission-map-heading-icon {
  display: none;
}

.subject-page--tdn .section-eyebrow {
  color: var(--tdn-blue);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: none;
}

.subject-page--tdn .section-title {
  margin: 2px 0 6px;
  color: var(--tdn-ink);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.subject-page--tdn .section-subtitle {
  margin: 0;
  color: var(--tdn-muted);
  font-size: 14px;
  line-height: 1.5;
}

.subject-page--tdn .tdn-set-accordion-layout .topic-list-stage {
  padding: 8px 12px 16px;
  background: transparent;
}

.subject-page--tdn .tdn-set-accordion-layout .practice-set.practice-set-accordion,
.subject-page--tdn .tdn-set-accordion-layout .practice-set.practice-set-accordion.is-expanded,
.subject-page--tdn .tdn-set-accordion-layout .practice-set.practice-set-accordion.is-complete:not(.is-expanded) {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-surface);
  box-shadow: none;
}

.subject-page--tdn .tdn-set-accordion-layout .practice-set.practice-set-accordion.is-expanded {
  border-color: color-mix(in srgb, var(--tdn-blue) 35%, var(--tdn-line));
  background: #fcfdff;
}

.subject-page--tdn .practice-set-accordion-trigger {
  min-height: 64px;
  padding: 12px 14px;
}

.subject-page--tdn .practice-set-accordion-trigger:hover {
  background: #f7f9fc;
}

.subject-page--tdn .practice-set-accordion.is-expanded .practice-set-accordion-trigger {
  background: transparent;
}

.subject-page--tdn .practice-set-accordion-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--tdn-blue-soft);
  color: var(--tdn-blue);
  box-shadow: none;
}

.subject-page--tdn .practice-set-accordion-trigger.is-complete .practice-set-accordion-icon {
  background: var(--tdn-green-soft);
  color: var(--tdn-green);
}

.subject-page--tdn .practice-set-accordion-trigger.is-in-progress .practice-set-accordion-icon {
  background: var(--tdn-amber-soft);
  color: var(--tdn-amber);
}

.subject-page--tdn .practice-set-accordion-title small {
  color: var(--tdn-muted);
  font-weight: 600;
}

.subject-page--tdn .practice-set-accordion-progress i {
  height: 8px;
  background: #eef1f6;
}

.subject-page--tdn .practice-set-accordion-progress i span {
  background: var(--tdn-blue);
}

.subject-page--tdn .tdn-mock-set-cta {
  margin: 8px 12px 12px;
  padding: 12px 14px;
  border: 1px solid var(--tdn-line);
  border-radius: 10px;
  background: #f7f9fc;
}

.subject-page--tdn .tdn-mock-set-cta button,
.subject-page--tdn .tdn-mock-set-cta a.button-link {
  min-height: 40px;
  border-radius: 10px;
  background: var(--tdn-blue);
  color: #fff;
  font-weight: 700;
}

.subject-page--tdn .tdn-mock-set-cta .is-secondary {
  background: #fff;
  color: var(--tdn-ink);
  border: 1px solid var(--tdn-line-strong);
}

.subject-page--tdn .practice-topic-finder,
.subject-page--tdn .practice-topic-resume {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-blue-soft);
  box-shadow: none;
}

.subject-page--tdn .practice-topic-resume span {
  color: var(--tdn-blue);
  font-weight: 700;
}

/* ------------------------------------------------------------------ */
/* Practice quiz (TDN only)                                            */
/* ------------------------------------------------------------------ */

.practice-app:has(.practice-shell[data-subject-id="thi-tran-dai-nghia"]) {
  background: var(--tdn-bg, #f7f8fa);
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] {
  gap: 16px;
  background: transparent;
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .practice-topbar {
  width: min(760px, 100%);
  margin: 0 auto;
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .back-button,
.practice-shell[data-subject-id="thi-tran-dai-nghia"] .practice-progress-chip {
  border: 1px solid var(--tdn-line);
  border-radius: 10px;
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .practice-progress-chip strong {
  color: var(--tdn-blue);
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .practice-panel,
.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-card {
  width: min(760px, 100%);
  margin-inline: auto;
  padding: 22px 24px;
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn {
  min-height: 52px;
  border: 1.5px solid var(--tdn-line);
  border-radius: 12px;
  box-shadow: none;
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn:hover,
.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn:focus-visible {
  border-color: var(--tdn-blue);
  background: var(--tdn-blue-soft);
  box-shadow: none;
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn.is-selected {
  border-color: var(--tdn-blue);
  background: var(--tdn-blue-soft);
  box-shadow: inset 0 0 0 1px var(--tdn-blue);
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-badge {
  background: #eef1f6;
  color: var(--tdn-ink);
  border-radius: 8px;
  font-weight: 700;
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn.is-selected .question-choice-badge,
.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-check {
  background: var(--tdn-blue);
  color: #fff;
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn.is-correct {
  border-color: var(--tdn-green);
  background: var(--tdn-green-soft);
  box-shadow: none;
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn.is-correct .question-choice-badge,
.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn.is-correct .question-choice-check {
  background: var(--tdn-green);
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn.is-wrong {
  border-color: var(--tdn-red);
  background: var(--tdn-red-soft);
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-choice-btn.is-wrong .question-choice-badge {
  background: var(--tdn-red);
  color: #fff;
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .button.primary {
  min-height: 44px;
  border-radius: 10px;
  background: var(--tdn-blue);
  box-shadow: none;
}

.practice-shell[data-subject-id="thi-tran-dai-nghia"] .tdn-ai-history-hero,
.tdn-improvement-app .tdn-ai-history-hero {
  width: min(880px, 100%);
  margin: 0 auto;
  padding: 22px 24px;
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.tdn-improvement-app {
  background: var(--tdn-bg);
}

.tdn-improvement-app .tdn-ai-report,
.practice-shell[data-subject-id="thi-tran-dai-nghia"] .tdn-ai-report {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

/* ------------------------------------------------------------------ */
/* 90-minute mock exam                                                 */
/* ------------------------------------------------------------------ */

.tdn-mock-app {
  background: var(--tdn-bg);
  color: var(--tdn-ink);
}

.tdn-mock-topbar,
.tdn-mock-exam-header {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.tdn-mock-topbar button,
.tdn-mock-exam-header > button:first-child {
  color: var(--tdn-muted);
  font-weight: 650;
}

.tdn-mock-kicker {
  color: var(--tdn-blue);
  font-weight: 700;
  letter-spacing: 0.01em;
}

.tdn-mock-hero,
.tdn-mock-transition-card,
.tdn-mock-result-hero,
.tdn-mock-question-card,
.tdn-mock-review-card,
.tdn-mock-advice-card {
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.tdn-mock-hero h1,
.tdn-mock-transition-card h1,
.tdn-mock-result-hero h1 {
  color: var(--tdn-ink);
  letter-spacing: -0.03em;
}

.tdn-mock-intro-grid div {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: #f7f9fc;
}

.tdn-mock-primary,
.tdn-mock-app .button.primary {
  min-height: 44px;
  border-radius: 10px;
  background: var(--tdn-blue);
  color: #fff;
  font-weight: 700;
}

.tdn-mock-primary:hover {
  background: var(--tdn-blue-hover);
}

.tdn-mock-secondary {
  min-height: 44px;
  border: 1px solid var(--tdn-line-strong);
  border-radius: 10px;
  background: var(--tdn-surface);
  color: var(--tdn-ink);
  font-weight: 650;
}

.tdn-mock-nav-btn {
  border: 1px solid var(--tdn-line);
  border-radius: 8px;
  background: var(--tdn-surface);
}

.tdn-mock-nav-btn.is-active {
  border-color: var(--tdn-blue);
  background: var(--tdn-blue-soft);
  color: var(--tdn-blue);
}

.tdn-mock-nav-btn.is-answered {
  background: var(--tdn-green-soft);
  border-color: color-mix(in srgb, var(--tdn-green) 30%, var(--tdn-line));
}

.tdn-mock-choice {
  border: 1.5px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-surface);
}

.tdn-mock-choice:hover,
.tdn-mock-choice:focus-visible {
  border-color: var(--tdn-blue);
  background: var(--tdn-blue-soft);
}

.tdn-mock-choice.is-selected {
  border-color: var(--tdn-blue);
  background: var(--tdn-blue-soft);
}

.tdn-mock-choice b {
  background: #eef1f6;
  color: var(--tdn-ink);
  font-weight: 700;
}

.tdn-mock-choice.is-selected b {
  background: var(--tdn-blue);
  color: #fff;
}

.tdn-mock-short-input,
.tdn-mock-textarea {
  border: 1.5px solid var(--tdn-line);
  border-radius: 10px;
}

.tdn-mock-short-input:focus,
.tdn-mock-textarea:focus {
  outline: none;
  border-color: var(--tdn-blue);
  box-shadow: var(--tdn-focus);
}

.tdn-mock-item-meta {
  color: var(--tdn-muted);
  font-size: 13px;
  font-weight: 650;
}

.tdn-mock-score-ring {
  border: 0;
  background: var(--tdn-blue-soft);
  color: var(--tdn-blue);
}

.tdn-mock-score-ring strong {
  font-size: 36px;
  font-weight: 800;
  line-height: 1;
}

.tdn-mock-section-card {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-surface);
}

/* ------------------------------------------------------------------ */
/* Section drills                                                      */
/* ------------------------------------------------------------------ */

.tdn-drill-app {
  background: var(--tdn-bg);
  color: var(--tdn-ink);
}

.tdn-drill-topbar {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.tdn-drill-topbar button {
  color: var(--tdn-muted);
}

.tdn-drill-hero,
.tdn-drill-repair,
.tdn-drill-card,
.tdn-drill-grid article {
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.tdn-drill-hero h1,
.tdn-drill-repair h2,
.tdn-drill-card h2,
.tdn-drill-grid h3 {
  color: var(--tdn-ink);
}

.tdn-drill-kicker,
.tdn-drill-repair > span,
.tdn-drill-grid span {
  color: var(--tdn-blue);
  font-weight: 700;
  letter-spacing: 0.01em;
  text-transform: none;
}

.tdn-drill-progress {
  background: #eef1f6;
}

.tdn-drill-progress i {
  background: var(--tdn-blue);
}

.tdn-drill-choice {
  border: 1.5px solid var(--tdn-line);
  border-radius: 12px;
}

.tdn-drill-choice.is-selected {
  border-color: var(--tdn-blue);
  background: var(--tdn-blue-soft);
}

.tdn-drill-choice.is-correct {
  border-color: var(--tdn-green);
  background: var(--tdn-green-soft);
}

.tdn-drill-choice.is-wrong {
  border-color: var(--tdn-red);
  background: var(--tdn-red-soft);
}

.tdn-drill-feedback.is-correct {
  background: var(--tdn-green-soft);
}

.tdn-drill-feedback.is-wrong {
  background: var(--tdn-red-soft);
}

.tdn-drill-input,
.tdn-drill-textarea {
  border: 1.5px solid var(--tdn-line);
  border-radius: 10px;
}

.tdn-drill-input:focus,
.tdn-drill-textarea:focus {
  outline: none;
  border-color: var(--tdn-blue);
  box-shadow: var(--tdn-focus);
}

.tdn-drill-passage {
  border-left: 3px solid var(--tdn-blue);
  background: #f7f9fc;
  color: var(--tdn-ink);
}

.tdn-drill-repair {
  background: var(--tdn-amber-soft);
  border-color: color-mix(in srgb, var(--tdn-amber) 28%, var(--tdn-line));
}

.tdn-drill-app .button.primary {
  min-height: 44px;
  border-radius: 10px;
  background: var(--tdn-blue);
  box-shadow: none;
}

/* ------------------------------------------------------------------ */
/* TDN-93 exam room                                                    */
/* ------------------------------------------------------------------ */

.tdn93-app {
  background: var(--tdn-bg);
  color: var(--tdn-ink);
}

.tdn93-topbar,
.tdn93-exam-header {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.tdn93-topbar button,
.tdn93-exam-header > button {
  color: var(--tdn-muted);
  font-weight: 650;
}

.tdn93-hero {
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  color: var(--tdn-ink);
  box-shadow: var(--tdn-shadow);
}

.tdn93-kicker,
.tdn93-dashboard-section > header span,
.tdn93-review-intro > span,
.tdn93-result-hero > div > span,
.tdn93-error-panel > span,
.tdn93-ready-panel > span {
  color: var(--tdn-blue);
  font-weight: 700;
  letter-spacing: 0.01em;
}

.tdn93-hero h1 {
  color: var(--tdn-ink);
  letter-spacing: -0.03em;
}

.tdn93-hero p {
  color: var(--tdn-muted);
}

.tdn93-readiness {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: #f7f9fc;
  color: var(--tdn-ink);
}

.tdn93-readiness > span {
  color: var(--tdn-muted);
}

.tdn93-readiness > strong {
  color: var(--tdn-blue);
}

.tdn93-readiness.is-ready {
  background: var(--tdn-green-soft);
}

.tdn93-readiness.is-ready > strong {
  color: var(--tdn-green);
}

.tdn93-hero p {
  color: var(--tdn-muted);
}

.tdn93-rules {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.tdn93-rules > div {
  padding: 14px;
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-surface);
}

.tdn93-rules strong {
  color: var(--tdn-ink);
}

.tdn93-rules span {
  color: var(--tdn-muted);
}

.tdn93-form-card {
  border: 1px solid var(--tdn-line);
  border-radius: 12px;
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.tdn93-form-number {
  background: var(--tdn-blue-soft);
  color: var(--tdn-blue);
  border-radius: 10px;
}

.tdn93-primary,
.tdn93-app .button.primary,
.tdn93-form-status button {
  min-height: 42px;
  border: 0;
  border-radius: 10px;
  background: var(--tdn-blue);
  color: #fff;
  font-weight: 700;
  cursor: pointer;
}

.tdn93-result-hero,
.tdn93-review-card,
.tdn93-error-panel,
.tdn93-ready-panel {
  border: 1px solid var(--tdn-line);
  border-radius: var(--tdn-radius-lg);
  background: var(--tdn-surface);
  box-shadow: var(--tdn-shadow);
}

.tdn93-score-ring {
  background: var(--tdn-blue-soft);
  color: var(--tdn-blue);
}

.tdn93-result-hero.is-high .tdn93-score-ring {
  background: var(--tdn-green-soft);
  color: var(--tdn-green);
}

/* ------------------------------------------------------------------ */
/* Responsive                                                          */
/* ------------------------------------------------------------------ */

@media (max-width: 860px) {
  .subject-page--tdn .subject-hero-main {
    grid-template-columns: 48px minmax(0, 1fr);
  }

  .subject-page--tdn .subject-hero-stats {
    grid-column: 1 / -1;
  }

  .subject-page--tdn .tdn-hub-practice,
  .subject-page--tdn .tdn93-home-banner,
  .subject-page--tdn .tdn-ai-overview {
    grid-template-columns: 1fr;
  }

  .tdn93-hero,
  .tdn93-rules {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .subject-page--tdn .subject-hero,
  .subject-page--tdn .tdn-90-section-board,
  .subject-page--tdn .tdn-drill-home-cards article,
  .subject-page--tdn .tdn93-home-banner,
  .subject-page--tdn .tdn-ai-overview {
    padding: 16px;
  }

  .subject-page--tdn .practice-set-accordion-trigger {
    grid-template-columns: 36px minmax(0, 1fr) 28px;
  }

  .subject-page--tdn .practice-set-accordion-progress {
    grid-column: 1 / -1;
  }

  .practice-shell[data-subject-id="thi-tran-dai-nghia"] .question-card,
  .practice-shell[data-subject-id="thi-tran-dai-nghia"] .practice-panel {
    padding: 16px;
  }
}