/* ============================================
   Clinical AI Boards — Dark Theme
   boards.clinicalai.guide
   ============================================ */

:root {
  --bg-primary: #0f1117;
  --bg-secondary: #1a1d2e;
  --bg-card: #222639;
  --bg-hover: #2a2f47;
  --text-primary: #e8eaf0;
  --text-secondary: #9ba1b5;
  --text-muted: #6b7185;
  --accent: #4fc3f7;
  --accent-hover: #29b6f6;
  --success: #66bb6a;
  --success-bg: rgba(102, 187, 106, 0.12);
  --error: #ef5350;
  --error-bg: rgba(239, 83, 80, 0.12);
  --warning: #ffa726;
  --border: #2e3348;
  --border-light: #3a3f57;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  --transition: 0.2s ease;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

/* ---- Layout ---- */

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 1.5rem;
}

header {
  text-align: center;
  padding: 2rem 0 1rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2rem;
}

header h1 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

header .subtitle {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-top: 0.25rem;
}

.user-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 0;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.user-bar .user-email {
  color: var(--text-secondary);
  font-size: 0.85rem;
}

.user-bar button {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.8rem;
  transition: var(--transition);
}

.user-bar button:hover {
  border-color: var(--text-secondary);
  color: var(--text-primary);
}

/* ---- Views ---- */

.view {
  display: none;
}

.view.active {
  display: block;
}

/* ---- Login ---- */

.login-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  max-width: 400px;
  margin: 3rem auto;
  box-shadow: var(--shadow);
}

.login-card h2 {
  font-size: 1.2rem;
  margin-bottom: 1.5rem;
  text-align: center;
}

.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
}

.form-group input {
  width: 100%;
  padding: 0.65rem 0.75rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: var(--transition);
}

.form-group input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(79, 195, 247, 0.15);
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  text-align: center;
}

.btn-primary {
  background: var(--accent);
  color: var(--bg-primary);
  width: 100%;
}

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

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

.btn-secondary {
  background: var(--bg-hover);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--border-light);
}

.login-error {
  color: var(--error);
  font-size: 0.85rem;
  margin-top: 0.75rem;
  text-align: center;
  min-height: 1.2em;
}

/* ---- Module Cards ---- */

.module-grid {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.module-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.module-card:hover {
  border-color: var(--accent);
  background: var(--bg-hover);
}

.module-card.completed {
  border-color: var(--success);
}

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

.module-card .module-number {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
}

.module-card.completed .module-number {
  color: var(--success);
}

.module-card .module-status {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.module-card .module-status .check-icon::before {
  content: '✓ ';
  color: var(--success);
}

.module-card .module-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.module-card .module-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

/* ---- Tier Selection (within a module) ---- */

.tier-select-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.tier-select-label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* ---- Tier Cards ---- */

.tier-grid {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.tier-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.tier-card:hover:not(.locked) {
  border-color: var(--accent);
  background: var(--bg-hover);
}

.tier-card.locked {
  opacity: 0.5;
  cursor: not-allowed;
}

.tier-card.completed {
  border-color: var(--success);
}

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

.tier-card .tier-number {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
}

.tier-card.completed .tier-number {
  color: var(--success);
}

.tier-card.locked .tier-number {
  color: var(--text-muted);
}

.tier-card .tier-status {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.tier-card .tier-status .lock-icon::before {
  content: '🔒 ';
}

.tier-card .tier-status .check-icon::before {
  content: '✓ ';
  color: var(--success);
}

.tier-card .tier-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

/* ---- Progress Bar ---- */

.progress-bar {
  height: 6px;
  background: var(--bg-primary);
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar .progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 3px;
  transition: width 0.4s ease;
}

.tier-card.completed .progress-fill {
  background: var(--success);
}

.progress-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.35rem;
}

/* ---- Quiz View ---- */

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.quiz-header .quiz-tier-label {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
}

.quiz-header .quiz-progress {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.quiz-progress-bar {
  margin-bottom: 2rem;
}

.question-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
}

.question-text {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 1.25rem;
}

.options-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.option-btn {
  display: block;
  width: 100%;
  text-align: left;
  padding: 0.75rem 1rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 0.9rem;
  line-height: 1.5;
  cursor: pointer;
  transition: var(--transition);
}

.option-btn:hover:not(:disabled) {
  border-color: var(--accent);
  background: var(--bg-hover);
}

.option-btn:disabled {
  cursor: default;
}

.option-btn.selected {
  border-color: var(--accent);
  background: rgba(79, 195, 247, 0.08);
}

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

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

/* ---- Feedback ---- */

.feedback {
  display: none;
  margin-top: 1.25rem;
  padding: 1rem 1.25rem;
  border-radius: var(--radius);
  font-size: 0.9rem;
  line-height: 1.6;
}

.feedback.visible {
  display: block;
}

.feedback.correct {
  background: var(--success-bg);
  border: 1px solid rgba(102, 187, 106, 0.25);
}

.feedback.incorrect {
  background: var(--error-bg);
  border: 1px solid rgba(239, 83, 80, 0.25);
}

.feedback .feedback-label {
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.feedback.correct .feedback-label {
  color: var(--success);
}

.feedback.incorrect .feedback-label {
  color: var(--error);
}

.feedback .explanation {
  color: var(--text-secondary);
}

.feedback .textbook-link {
  display: inline-block;
  margin-top: 0.5rem;
  color: var(--accent);
  text-decoration: none;
  font-size: 0.85rem;
}

.feedback .textbook-link:hover {
  text-decoration: underline;
}

.quiz-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.75rem;
  margin-top: 1rem;
}

.btn-back {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.9rem;
  transition: var(--transition);
}

.btn-back:hover {
  border-color: var(--text-secondary);
  color: var(--text-primary);
}

/* ---- Results View ---- */

.results-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  box-shadow: var(--shadow);
}

.results-card .results-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.results-card h2 {
  font-size: 1.3rem;
  margin-bottom: 0.5rem;
}

.results-card .results-score {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  margin: 1rem 0;
}

.results-card .results-score.passed {
  color: var(--success);
}

.results-card .results-score.failed {
  color: var(--error);
}

.results-card .results-message {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}

.results-card .results-detail {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.results-actions {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ---- Admin ---- */

.admin-container {
  max-width: 960px;
  margin: 0 auto;
  padding: 1.5rem;
}

.admin-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
  font-size: 0.9rem;
}

.admin-table th,
.admin-table td {
  padding: 0.65rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.admin-table th {
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  background: var(--bg-secondary);
  position: sticky;
  top: 0;
}

.admin-table td {
  color: var(--text-primary);
}

.admin-table tr:hover td {
  background: var(--bg-hover);
}

.admin-section {
  margin-bottom: 2.5rem;
}

.admin-section h2 {
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.score-high { color: var(--success); }
.score-mid { color: var(--warning); }
.score-low { color: var(--error); }

.admin-login-prompt {
  text-align: center;
  padding: 4rem 1rem;
  color: var(--text-secondary);
}

.admin-loading {
  text-align: center;
  padding: 3rem;
  color: var(--text-muted);
}

/* ---- Loading / Empty States ---- */

.loading {
  text-align: center;
  padding: 3rem;
  color: var(--text-muted);
}

.loading::after {
  content: '';
  display: inline-block;
  width: 1.25rem;
  height: 1.25rem;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-left: 0.5rem;
  vertical-align: middle;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ---- Interactive Questions ---- */

#interactive-area:empty {
  display: none;
}

.interactive-instruction {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  text-align: center;
}

/* --- Loss Curve --- */

.loss-curve-container {
  text-align: center;
}

.canvas-wrap {
  width: 100%;
  max-width: 600px;
  margin: 0 auto;
}

.canvas-wrap canvas {
  width: 100%;
  cursor: crosshair;
  border-radius: var(--radius);
}

.canvas-wrap canvas.answered {
  cursor: default;
}

.curve-legend {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 0.75rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.legend-swatch {
  display: inline-block;
  width: 20px;
  height: 3px;
  border-radius: 2px;
}

/* --- Confusion Matrix --- */

.cm-container {
  max-width: 380px;
  margin: 0 auto;
}

.cm-grid {
  display: grid;
  grid-template-columns: auto 1fr 1fr;
  gap: 3px;
  margin-bottom: 1.25rem;
}

.cm-cell {
  position: relative;
  padding: 0.75rem 0.5rem;
  text-align: center;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
}

.cm-cell.cm-corner {
  background: transparent;
}

.cm-cell.cm-header {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.cm-cell.cm-row-header {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding-right: 0.75rem;
  text-align: right;
  justify-content: flex-end;
}

.cm-cell.cm-tp, .cm-cell.cm-tn {
  background: rgba(102, 187, 106, 0.1);
  border: 1px solid rgba(102, 187, 106, 0.2);
  flex-direction: column;
  gap: 0.15rem;
  padding: 1rem 0.75rem;
}

.cm-cell.cm-fp, .cm-cell.cm-fn {
  background: rgba(239, 83, 80, 0.1);
  border: 1px solid rgba(239, 83, 80, 0.2);
  flex-direction: column;
  gap: 0.15rem;
  padding: 1rem 0.75rem;
}

.cm-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
}

.cm-label {
  font-size: 0.65rem;
  font-weight: 400;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.cm-prompt {
  font-size: 0.9rem;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.cm-formula-hint {
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  padding: 0.4rem 0.6rem;
  background: var(--bg-primary);
  border-radius: var(--radius);
  display: inline-block;
}

.cm-input-row {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  margin-bottom: 0.35rem;
}

.cm-input {
  width: 100px;
  padding: 0.65rem 0.75rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 1rem;
  text-align: center;
  transition: var(--transition);
}

.cm-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(79, 195, 247, 0.15);
}

.cm-submit {
  width: auto;
  padding: 0.65rem 1.25rem;
}

.cm-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* --- Pipeline Spotter --- */

.pipeline-container {
  margin: 0.5rem 0;
}

.pipeline-row {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  overflow-x: auto;
  padding: 0.75rem 0;
  -webkit-overflow-scrolling: touch;
}

.pipeline-step {
  flex: 0 0 auto;
  width: 140px;
  min-height: 80px;
  background: var(--bg-primary);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 0.5rem;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  color: var(--text-primary);
  font-size: 0.8rem;
  line-height: 1.4;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.25rem;
}

.pipeline-step:hover:not(.answered) {
  border-color: var(--accent);
  background: var(--bg-hover);
}

.pipeline-step-num {
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.pipeline-step-label {
  font-size: 0.8rem;
  line-height: 1.4;
}

.pipeline-step.answered {
  cursor: default;
}

.pipeline-step.correct-step {
  border-color: var(--success);
  background: var(--success-bg);
}

.pipeline-step.incorrect-click {
  border-color: var(--error);
  background: var(--error-bg);
}

.pipeline-step.leaky-highlight {
  border-color: var(--warning);
  background: rgba(255, 167, 38, 0.12);
}

.pipeline-step.safe-step {
  opacity: 0.5;
}

.pipeline-arrow {
  flex: 0 0 auto;
  color: var(--text-muted);
  font-size: 1.2rem;
  padding: 0 0.15rem;
}

/* --- Shared Interactive Button (classifier-btn, used in multiple types) --- */

.classifier-container,
.curve-diag-container,
.windowing-container,
.aug-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.classifier-row {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
}

.classifier-scenario {
  font-size: 0.9rem;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  line-height: 1.5;
}

.classifier-btns,
.curve-diag-btns,
.windowing-btns,
.aug-btns,
.imputation-btns {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.classifier-btn {
  padding: 0.45rem 0.85rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
}

.classifier-btn:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--text-primary);
}

.classifier-btn.selected {
  border-color: var(--accent);
  background: rgba(79, 195, 247, 0.1);
  color: var(--accent);
}

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

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

/* --- EDA Red Flag Spotter --- */

.redflag-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.redflag-info {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.redflag-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
  overflow-x: auto;
  display: block;
}

.redflag-table thead {
  position: sticky;
  top: 0;
}

.redflag-table th {
  padding: 0.5rem;
  text-align: left;
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

.redflag-table td {
  padding: 0.5rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
  white-space: nowrap;
}

.redflag-row {
  transition: var(--transition);
}

.redflag-row:hover {
  background: var(--bg-hover);
}

.redflag-row.flagged {
  background: rgba(79, 195, 247, 0.08);
  outline: 1px solid var(--accent);
  outline-offset: -1px;
}

.redflag-row.flag-correct {
  background: var(--success-bg);
  outline: 1px solid rgba(102, 187, 106, 0.3);
  outline-offset: -1px;
}

.redflag-row.flag-missed {
  background: rgba(255, 167, 38, 0.1);
  outline: 1px dashed var(--warning);
  outline-offset: -1px;
}

.redflag-row.flag-wrong {
  background: var(--error-bg);
  outline: 1px solid rgba(239, 83, 80, 0.3);
  outline-offset: -1px;
}

.flag-reason {
  font-size: 0.75rem;
  color: var(--warning);
  padding: 0.25rem 0.5rem;
  font-style: italic;
}

/* --- Imputation Strategy Picker --- */

.imputation-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.imputation-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
}

.imputation-header {
  font-size: 0.9rem;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}

.imputation-context {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  line-height: 1.4;
}

.imputation-btn {
  padding: 0.45rem 0.85rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
}

.imputation-btn:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--text-primary);
}

.imputation-btn.selected {
  border-color: var(--accent);
  background: rgba(79, 195, 247, 0.1);
  color: var(--accent);
}

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

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

.imputation-explanation {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
  font-style: italic;
}

/* --- DICOM Tag Matcher --- */

.tag-matcher-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.tag-matcher-row {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  transition: var(--transition);
}

.tag-matcher-row.match-correct {
  border-color: var(--success);
  background: var(--success-bg);
}

.tag-matcher-row.match-incorrect {
  border-color: var(--error);
  background: var(--error-bg);
}

.tag-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tag-code {
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.8rem;
  color: var(--accent);
  background: var(--bg-card);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
}

.tag-name {
  font-size: 0.85rem;
  color: var(--text-primary);
  font-weight: 500;
}

.tag-select {
  width: 100%;
  padding: 0.5rem 0.65rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition);
  appearance: auto;
}

.tag-select:focus {
  outline: none;
  border-color: var(--accent);
}

.tag-select:disabled {
  opacity: 0.7;
  cursor: default;
}

.match-correction {
  font-size: 0.8rem;
  color: var(--success);
  margin-top: 0.25rem;
  font-weight: 500;
}

/* --- Windowing Challenge --- */

.windowing-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
}

.windowing-task {
  font-size: 0.9rem;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  line-height: 1.5;
}

.windowing-btn {
  padding: 0.5rem 0.85rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  line-height: 1.4;
}

.windowing-btn:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--text-primary);
}

.windowing-btn.selected {
  border-color: var(--accent);
  background: rgba(79, 195, 247, 0.1);
  color: var(--accent);
}

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

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

.windowing-params {
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.7rem;
  color: var(--text-muted);
}

/* --- Preprocessing Pipeline Builder --- */

.preprocess-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.preprocess-context {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  padding: 0.65rem 0.85rem;
  background: var(--bg-primary);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.preprocess-display {
  min-height: 48px;
  padding: 0.75rem;
  background: var(--bg-primary);
  border: 1px dashed var(--border-light);
  border-radius: var(--radius);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem;
}

.preprocess-empty {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-style: italic;
}

.preprocess-label {
  font-size: 0.8rem;
  color: var(--success);
  font-weight: 600;
  margin-right: 0.5rem;
}

.preprocess-chip {
  display: inline-block;
  padding: 0.3rem 0.6rem;
  background: var(--bg-card);
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  font-size: 0.75rem;
  color: var(--accent);
}

.preprocess-chip.correct {
  border-color: var(--success);
  color: var(--success);
  background: var(--success-bg);
}

.preprocess-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.preprocess-step-btn {
  padding: 0.55rem 0.85rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
}

.preprocess-step-btn:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--text-primary);
}

.preprocess-step-btn.selected {
  border-color: var(--accent);
  background: rgba(79, 195, 247, 0.1);
  color: var(--accent);
}

.preprocess-step-btn.correct {
  border-color: var(--success);
  background: var(--success-bg);
  color: var(--success);
}

.preprocess-step-btn.incorrect {
  border-color: var(--error);
  background: var(--error-bg);
  color: var(--error);
}

.preprocess-step-btn.missed {
  border-color: var(--warning);
  background: rgba(255, 167, 38, 0.1);
  color: var(--warning);
}

.step-wrong-reason {
  font-size: 0.75rem;
  color: var(--error);
  padding: 0.25rem 0;
  font-style: italic;
}

/* --- Architecture Builder --- */

.arch-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.arch-description {
  font-size: 0.9rem;
  color: var(--text-primary);
  line-height: 1.6;
  padding: 0.85rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.arch-field {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.65rem 0.85rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.arch-field-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.arch-field-value {
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 600;
}

.arch-explanation {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.5;
  padding: 0.65rem 0.85rem;
  background: var(--bg-primary);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  font-style: italic;
}

/* --- Training Curve Diagnosis --- */

.curve-diag-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
}

.curve-diag-title {
  font-size: 0.9rem;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.curve-diag-data {
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  padding: 0.5rem 0.75rem;
  background: var(--bg-card);
  border-radius: var(--radius);
  line-height: 1.6;
}

.curve-label {
  font-weight: 600;
}

.curve-label.train {
  color: var(--accent);
}

.curve-label.val {
  color: var(--warning);
}

.curve-diag-fix {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
}

/* --- Augmentation Picker --- */

.aug-context {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  padding: 0.65rem 0.85rem;
  background: var(--bg-primary);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.aug-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  flex-wrap: wrap;
}

.aug-name {
  font-size: 0.9rem;
  color: var(--text-primary);
  font-weight: 500;
  flex: 1;
  min-width: 120px;
}

.aug-btn {
  padding: 0.4rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
  background: var(--bg-card);
  color: var(--text-secondary);
}

.aug-btn:hover:not(:disabled) {
  color: var(--text-primary);
}

.aug-btn.safe:hover:not(:disabled) {
  border-color: var(--success);
}

.aug-btn.dangerous:hover:not(:disabled) {
  border-color: var(--error);
}

.aug-btn.selected.safe {
  border-color: var(--success);
  background: var(--success-bg);
  color: var(--success);
}

.aug-btn.selected.dangerous {
  border-color: var(--error);
  background: var(--error-bg);
  color: var(--error);
}

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

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

.aug-explanation {
  width: 100%;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
  font-style: italic;
}

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

@media (max-width: 600px) {
  .container {
    padding: 1rem;
  }

  header {
    padding: 1.5rem 0 0.75rem;
    margin-bottom: 1.5rem;
  }

  header h1 {
    font-size: 1.25rem;
  }

  .login-card {
    margin: 1.5rem auto;
    padding: 1.5rem;
  }

  .question-card {
    padding: 1.25rem;
  }

  .results-card {
    padding: 1.5rem;
  }

  .quiz-actions {
    flex-direction: column;
  }

  .quiz-actions .btn {
    width: 100%;
  }

  .results-actions {
    flex-direction: column;
  }

  .results-actions .btn {
    width: 100%;
  }

  .pipeline-step {
    width: 110px;
    min-height: 70px;
    font-size: 0.75rem;
  }

  .cm-container {
    max-width: 100%;
  }

  .cm-value {
    font-size: 1.2rem;
  }

  .cm-cell.cm-tp, .cm-cell.cm-tn,
  .cm-cell.cm-fp, .cm-cell.cm-fn {
    padding: 0.75rem 0.5rem;
  }

  .classifier-btns,
  .curve-diag-btns,
  .windowing-btns,
  .aug-btns,
  .imputation-btns {
    flex-direction: column;
  }

  .redflag-table {
    font-size: 0.7rem;
  }

  .redflag-table th,
  .redflag-table td {
    padding: 0.35rem;
  }

  .aug-row {
    flex-direction: column;
    align-items: flex-start;
  }

  .aug-btns {
    flex-direction: row;
  }

  .tag-matcher-row {
    padding: 0.65rem;
  }

  .preprocess-grid {
    gap: 0.35rem;
  }

  .preprocess-step-btn {
    font-size: 0.75rem;
    padding: 0.4rem 0.65rem;
  }
}