/* ═══════════════════════════════════════════
   EDUCATION QUIZ – CSS
   ═══════════════════════════════════════════ */

/* ── Grade Selector Grid ── */
.edu-grade-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 12px;
  padding: 8px 0;
}

.edu-grade-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 20px 12px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.3s var(--ease-out);
  overflow: hidden;
}

.edu-grade-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(94,106,210,0.08), rgba(130,143,255,0.04));
  opacity: 0;
  transition: opacity 0.3s;
}

.edu-grade-card:hover {
  border-color: var(--accent-blue);
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

.edu-grade-card:hover::before { opacity: 1; }

.edu-grade-card.active {
  border-color: var(--accent-blue);
  background: rgba(94,106,210,0.1);
}

.edu-grade-number {
  font-family: var(--font-heading);
  font-size: 28px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  position: relative;
}

.edu-grade-label {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 6px;
  font-weight: 500;
  position: relative;
}

/* ── Subject Selector ── */
.edu-subject-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 12px;
  padding: 8px 0;
}

.edu-subject-card {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.3s var(--ease-out);
}

.edu-subject-card:hover {
  border-color: var(--accent-blue);
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

.edu-subject-card .subject-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.edu-subject-card .subject-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.edu-subject-card .subject-name {
  font-weight: 600;
  font-size: 14px;
  color: var(--text-primary);
}

.edu-subject-card .subject-count {
  font-size: 11px;
  color: var(--text-muted);
}

/* Subject color variants */
.edu-subject-card[data-subject="toan"] .subject-icon { background: rgba(94,106,210,0.15); color: var(--accent-blue); }
.edu-subject-card[data-subject="ly"] .subject-icon { background: rgba(79,195,247,0.15); color: var(--accent-cyan); }
.edu-subject-card[data-subject="hoa"] .subject-icon { background: rgba(239,83,80,0.15); color: var(--accent-red); }
.edu-subject-card[data-subject="sinh"] .subject-icon { background: rgba(39,166,68,0.15); color: var(--accent-green); }
.edu-subject-card[data-subject="van"] .subject-icon { background: rgba(255,202,40,0.15); color: var(--accent-yellow); }
.edu-subject-card[data-subject="anh"] .subject-icon { background: rgba(130,143,255,0.15); color: var(--accent-purple); }
.edu-subject-card[data-subject="su"] .subject-icon { background: rgba(255,112,67,0.15); color: var(--accent-orange); }
.edu-subject-card[data-subject="dia"] .subject-icon { background: rgba(52,211,153,0.15); color: #34d399; }
.edu-subject-card[data-subject="gdcd"] .subject-icon { background: rgba(251,191,36,0.15); color: #fbbf24; }
.edu-subject-card[data-subject="tin"] .subject-icon { background: rgba(96,165,250,0.15); color: #60a5fa; }

/* ── Breadcrumb / Navigation Path ── */
.edu-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 0 16px;
  font-size: 13px;
  color: var(--text-muted);
  flex-wrap: wrap;
}

.edu-breadcrumb-item {
  background: none;
  border: none;
  color: var(--accent-blue);
  cursor: pointer;
  font-size: 13px;
  padding: 0;
  font-family: inherit;
  transition: color 0.2s;
}

.edu-breadcrumb-item:hover { color: var(--accent-purple); text-decoration: underline; }

.edu-breadcrumb-sep {
  color: var(--text-muted);
  opacity: 0.5;
}

.edu-breadcrumb-current {
  color: var(--text-primary);
  font-weight: 600;
}

/* ── Quiz Container ── */
.edu-quiz-container {
  max-width: 720px;
  margin: 0 auto;
}

/* ── Progress Bar ── */
.edu-progress-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
}

.edu-progress-bar {
  flex: 1;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
}

.edu-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-purple));
  border-radius: 3px;
  transition: width 0.4s var(--ease-out);
}

.edu-progress-text {
  font-size: 13px;
  color: var(--text-muted);
  white-space: nowrap;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* ── Question Card ── */
.edu-question-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  animation: eduFadeIn 0.3s var(--ease-out);
}

@keyframes eduFadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.edu-question-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.edu-question-badge {
  font-size: 11px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.edu-question-badge.easy { background: rgba(39,166,68,0.12); color: var(--accent-green); }
.edu-question-badge.medium { background: rgba(255,202,40,0.12); color: var(--accent-yellow); }
.edu-question-badge.hard { background: rgba(239,83,80,0.12); color: var(--accent-red); }

.edu-question-number {
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 500;
}

.edu-question-text {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.6;
  margin: 16px 0 24px;
}

/* ── Answer Options ── */
.edu-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.edu-option {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s var(--ease-out);
  font-size: 15px;
  color: var(--text-primary);
}

.edu-option:hover {
  border-color: var(--accent-blue);
  background: rgba(94,106,210,0.06);
}

.edu-option-letter {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 700;
  color: var(--text-muted);
  flex-shrink: 0;
  transition: all 0.2s;
}

.edu-option:hover .edu-option-letter {
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

.edu-option.selected {
  border-color: var(--accent-blue);
  background: rgba(94,106,210,0.1);
}

.edu-option.selected .edu-option-letter {
  background: var(--accent-blue);
  border-color: var(--accent-blue);
  color: #fff;
}

.edu-option.correct {
  border-color: var(--accent-green);
  background: rgba(39,166,68,0.1);
}

.edu-option.correct .edu-option-letter {
  background: var(--accent-green);
  border-color: var(--accent-green);
  color: #fff;
}

.edu-option.wrong {
  border-color: var(--accent-red);
  background: rgba(239,83,80,0.08);
}

.edu-option.wrong .edu-option-letter {
  background: var(--accent-red);
  border-color: var(--accent-red);
  color: #fff;
}

.edu-option.disabled { pointer-events: none; opacity: 0.6; }

/* ── Explanation ── */
.edu-explanation {
  margin-top: 16px;
  padding: 14px 18px;
  background: rgba(94,106,210,0.06);
  border-left: 3px solid var(--accent-blue);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
  animation: eduFadeIn 0.3s var(--ease-out);
}

.edu-explanation i {
  color: var(--accent-blue);
  margin-right: 6px;
}

/* ── Quiz Actions ── */
.edu-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 20px;
}

.edu-btn {
  padding: 10px 24px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s var(--ease-out);
  font-family: var(--font-sans);
}

.edu-btn-primary {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  color: #fff;
}

.edu-btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(94,106,210,0.3);
}

.edu-btn-primary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

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

.edu-btn-secondary:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
}

/* ── Results Screen ── */
.edu-results {
  text-align: center;
  animation: eduFadeIn 0.4s var(--ease-out);
}

.edu-results-score {
  position: relative;
  width: 180px;
  height: 180px;
  margin: 0 auto 24px;
}

.edu-score-ring {
  transform: rotate(-90deg);
}

.edu-score-track {
  fill: none;
  stroke: var(--border);
  stroke-width: 8;
}

.edu-score-progress {
  fill: none;
  stroke-width: 8;
  stroke-linecap: round;
  transition: stroke-dashoffset 1.5s var(--ease-out);
}

.edu-score-value {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}

.edu-score-number {
  font-family: var(--font-heading);
  font-size: 42px;
  font-weight: 800;
  line-height: 1;
}

.edu-score-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 4px;
  font-weight: 500;
}

.edu-results-grade {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 8px;
}

.edu-results-summary {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 24px;
}

/* ── Result Stats Grid ── */
.edu-stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 24px;
}

.edu-stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 16px;
  text-align: center;
}

.edu-stat-value {
  font-size: 24px;
  font-weight: 800;
  font-family: var(--font-heading);
}

.edu-stat-value.correct { color: var(--accent-green); }
.edu-stat-value.wrong { color: var(--accent-red); }
.edu-stat-value.total { color: var(--accent-blue); }

.edu-stat-label {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 4px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ── Answer Review ── */
.edu-review-list {
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 24px;
}

.edu-review-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-size: 14px;
}

.edu-review-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  flex-shrink: 0;
}

.edu-review-icon.correct {
  background: rgba(39,166,68,0.15);
  color: var(--accent-green);
}

.edu-review-icon.wrong {
  background: rgba(239,83,80,0.12);
  color: var(--accent-red);
}

.edu-review-text {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--text-secondary);
}

/* ── History Section ── */
.edu-history-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  font-size: 13px;
}

.edu-history-table th {
  background: var(--bg-secondary);
  padding: 10px 14px;
  text-align: left;
  font-weight: 600;
  color: var(--text-muted);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-bottom: 1px solid var(--border);
}

.edu-history-table td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
}

.edu-history-table tr:hover td {
  background: var(--bg-card-hover);
}

/* ── No Questions State ── */
.edu-empty-state {
  text-align: center;
  padding: 48px 24px;
  color: var(--text-muted);
}

.edu-empty-state i {
  font-size: 48px;
  margin-bottom: 16px;
  opacity: 0.3;
}

.edu-empty-state p {
  font-size: 15px;
  line-height: 1.5;
}

/* ── Loading Spinner ── */
.edu-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 48px;
  color: var(--text-muted);
}

.edu-spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border);
  border-top-color: var(--accent-blue);
  border-radius: 50%;
  animation: eduSpin 0.8s linear infinite;
}

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

/* ── Tab Bar for quiz mode ── */
.edu-tab-bar {
  display: flex;
  gap: 6px;
  margin-bottom: 20px;
  padding: 4px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.edu-tab {
  flex: 1;
  padding: 10px 16px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  border-radius: calc(var(--radius-md) - 2px);
  transition: all 0.2s var(--ease-out);
  font-family: var(--font-sans);
}

.edu-tab:hover { color: var(--text-primary); }

.edu-tab.active {
  background: var(--accent-blue);
  color: #fff;
}

/* ── Section Header ── */
.edu-section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  flex-wrap: wrap;
  gap: 12px;
}

.edu-section-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.edu-section-title i {
  color: var(--accent-blue);
  font-size: 14px;
}

/* ── Difficulty Selector ── */
.edu-difficulty-pills {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.edu-diff-pill {
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: transparent;
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  font-family: var(--font-sans);
}

.edu-diff-pill:hover { border-color: var(--accent-blue); color: var(--text-primary); }

.edu-diff-pill.active {
  background: var(--accent-blue);
  border-color: var(--accent-blue);
  color: #fff;
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .edu-grade-grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
  }

  .edu-grade-card { padding: 14px 8px; }
  .edu-grade-number { font-size: 22px; }

  .edu-subject-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
  }

  .edu-question-card { padding: 20px 16px; }
  .edu-question-text { font-size: 15px; }
  .edu-option { padding: 12px 14px; font-size: 14px; }

  .edu-stats-grid { grid-template-columns: repeat(3, 1fr); gap: 8px; }
  .edu-stat-value { font-size: 20px; }

  .edu-results-score { width: 140px; height: 140px; }
  .edu-score-number { font-size: 34px; }
}

@media (max-width: 480px) {
  .edu-grade-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ── AI Toggle Switch ── */
.edu-switch {
  position: relative;
  display: inline-block;
  width: 44px;
  height: 24px;
}

.edu-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.edu-slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--border-color, #e2e8f0);
  transition: .3s;
  border-radius: 24px;
}

.edu-slider:before {
  position: absolute;
  content: "";
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: .3s;
  border-radius: 50%;
  box-shadow: 0 1px 3px rgba(0,0,0,0.15);
}

.edu-switch input:checked + .edu-slider {
  background-color: #a855f7; /* Purple for AI magic */
}

.edu-switch input:checked + .edu-slider:before {
  transform: translateX(20px);
}