/**
 * NTMK Mistake Notebook Styling — TypeUI Creative & Athenaeum Codex
 * Deep obsidian glassmorphism, responsive alignment, crisp badges, zero raw emoji
 * Leitner Spaced Repetition 4-Box Grid, Error Categorization & 1-Click Custom Exam
 */

.mistake-notebook-wrapper {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px 20px 80px;
}

/* ─── 1. Header Hero Deck ─── */
.mistake-header-banner {
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.95) 0%, rgba(15, 23, 42, 0.98) 100%);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 20px;
  padding: 32px 30px;
  margin-bottom: 24px;
  box-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.35);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  color: #f8fafc;
}

:root:not([data-theme="dark"]) .mistake-header-banner {
  background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
  border-color: #e2e8f0;
  color: #0f172a;
  box-shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.08);
}

.mistake-banner-left {
  flex: 1;
  min-width: 300px;
}

.mistake-banner-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #fbbf24;
  background: rgba(245, 158, 11, 0.15);
  border: 1px solid rgba(245, 158, 11, 0.3);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 12px;
}

:root:not([data-theme="dark"]) .mistake-banner-badge {
  background: #fef3c7;
  color: #b45309;
  border-color: #fcd34d;
}

.live-dot-pulse {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: #10b981;
  box-shadow: 0 0 8px #10b981;
  animation: pulse-glow 2s infinite;
}

@keyframes pulse-glow {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.2); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.mistake-title {
  font-size: 2rem;
  font-weight: 800;
  color: #f8fafc;
  margin: 0 0 10px;
  display: flex;
  align-items: center;
  gap: 12px;
}

:root:not([data-theme="dark"]) .mistake-title {
  color: #0f172a;
}

.title-icon-box {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(124, 58, 237, 0.3) 0%, rgba(99, 102, 241, 0.15) 100%);
  border: 1px solid rgba(124, 58, 237, 0.4);
  color: #c084fc;
}

:root:not([data-theme="dark"]) .title-icon-box {
  background: #ede9fe;
  border-color: #c4b5fd;
  color: #7c3aed;
}

.mistake-subtitle {
  font-size: 0.95rem;
  color: #94a3b8;
  margin: 0;
  max-width: 580px;
  line-height: 1.6;
}

:root:not([data-theme="dark"]) .mistake-subtitle {
  color: #475569;
}

.mistake-stats-cards {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.mistake-stat-card {
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 14px;
  padding: 14px 20px;
  text-align: center;
  min-width: 105px;
  backdrop-filter: blur(10px);
  transition: transform 0.2s ease, border-color 0.2s ease;
}

:root:not([data-theme="dark"]) .mistake-stat-card {
  background: #ffffff;
  border-color: #e2e8f0;
  box-shadow: 0 2px 8px rgba(15, 23, 42, 0.04);
}

.mistake-stat-card:hover {
  transform: translateY(-2px);
  border-color: rgba(255, 255, 255, 0.2);
}

:root:not([data-theme="dark"]) .mistake-stat-card:hover {
  border-color: #cbd5e1;
}

.mistake-stat-card .stat-num {
  display: block;
  font-size: 1.6rem;
  font-weight: 800;
  line-height: 1.2;
}

.mistake-stat-card .stat-label {
  font-size: 0.75rem;
  color: #94a3b8;
  font-weight: 600;
  margin-top: 4px;
}

:root:not([data-theme="dark"]) .mistake-stat-card .stat-label {
  color: #64748b;
}

.active-card .stat-num { color: #f87171; }
.due-card .stat-num { color: #fbbf24; }
.mastered-card .stat-num { color: #34d399; }
.rate-card .stat-num { color: #60a5fa; }

:root:not([data-theme="dark"]) .active-card .stat-num { color: #dc2626; }
:root:not([data-theme="dark"]) .due-card .stat-num { color: #d97706; }
:root:not([data-theme="dark"]) .mastered-card .stat-num { color: #059669; }
:root:not([data-theme="dark"]) .rate-card .stat-num { color: #2563eb; }

/* ─── 2. Leitner Spaced Repetition 4-Boxes Grid ─── */
.leitner-boxes-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-bottom: 24px;
}

.leitner-box-card {
  position: relative;
  background: rgba(30, 41, 59, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 16px;
  padding: 18px 16px;
  cursor: pointer;
  backdrop-filter: blur(12px);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease, background 0.2s ease;
  display: flex;
  flex-direction: column;
  color: #f8fafc;
}

[data-theme="dark"] .leitner-box-card {
  background: rgba(15, 23, 42, 0.85);
  border-color: rgba(255, 255, 255, 0.1);
}

:root:not([data-theme="dark"]) .leitner-box-card {
  background: #ffffff;
  border-color: #e2e8f0;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.05);
  color: #0f172a;
}

.leitner-box-card:hover {
  transform: translateY(-3px);
  border-color: rgba(255, 255, 255, 0.25);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}

:root:not([data-theme="dark"]) .leitner-box-card:hover {
  border-color: #cbd5e1;
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.09);
}

.leitner-box-card.selected {
  outline: 2px solid #8b5cf6;
  outline-offset: 2px;
  box-shadow: 0 0 20px rgba(139, 92, 246, 0.35);
}

:root:not([data-theme="dark"]) .leitner-box-card.selected {
  background: #faf5ff;
  border-color: #a855f7;
}

.leitner-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.leitner-badge {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 3px 8px;
  border-radius: 999px;
}

.box-1 .leitner-badge { background: rgba(239, 68, 68, 0.15); color: #f87171; border: 1px solid rgba(239, 68, 68, 0.3); }
.box-2 .leitner-badge { background: rgba(245, 158, 11, 0.15); color: #fbbf24; border: 1px solid rgba(245, 158, 11, 0.3); }
.box-3 .leitner-badge { background: rgba(59, 130, 246, 0.15); color: #60a5fa; border: 1px solid rgba(59, 130, 246, 0.3); }
.box-4 .leitner-badge { background: rgba(16, 185, 129, 0.15); color: #34d399; border: 1px solid rgba(16, 185, 129, 0.3); }

:root:not([data-theme="dark"]) .box-1 .leitner-badge { background: #fee2e2; color: #b91c1c; border-color: #fca5a5; }
:root:not([data-theme="dark"]) .box-2 .leitner-badge { background: #fef3c7; color: #b45309; border-color: #fcd34d; }
:root:not([data-theme="dark"]) .box-3 .leitner-badge { background: #dbeafe; color: #1d4ed8; border-color: #93c5fd; }
:root:not([data-theme="dark"]) .box-4 .leitner-badge { background: #d1fae5; color: #047857; border-color: #6ee7b7; }

.leitner-icon-box {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 8px;
}

.box-1 .leitner-icon-box { background: rgba(239, 68, 68, 0.12); color: #f87171; }
.box-2 .leitner-icon-box { background: rgba(245, 158, 11, 0.12); color: #fbbf24; }
.box-3 .leitner-icon-box { background: rgba(59, 130, 246, 0.12); color: #60a5fa; }
.box-4 .leitner-icon-box { background: rgba(16, 185, 129, 0.12); color: #34d399; }

:root:not([data-theme="dark"]) .box-1 .leitner-icon-box { background: #fee2e2; color: #dc2626; }
:root:not([data-theme="dark"]) .box-2 .leitner-icon-box { background: #fef3c7; color: #d97706; }
:root:not([data-theme="dark"]) .box-3 .leitner-icon-box { background: #dbeafe; color: #2563eb; }
:root:not([data-theme="dark"]) .box-4 .leitner-icon-box { background: #d1fae5; color: #059669; }

.leitner-count {
  font-size: 1.85rem;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 4px;
}

.box-1 .leitner-count { color: #f87171; }
.box-2 .leitner-count { color: #fbbf24; }
.box-3 .leitner-count { color: #60a5fa; }
.box-4 .leitner-count { color: #34d399; }

:root:not([data-theme="dark"]) .box-1 .leitner-count { color: #dc2626; }
:root:not([data-theme="dark"]) .box-2 .leitner-count { color: #d97706; }
:root:not([data-theme="dark"]) .box-3 .leitner-count { color: #2563eb; }
:root:not([data-theme="dark"]) .box-4 .leitner-count { color: #059669; }

.leitner-label {
  font-size: 0.88rem;
  font-weight: 700;
  color: #f1f5f9;
  margin-bottom: 3px;
}

:root:not([data-theme="dark"]) .leitner-label {
  color: #0f172a;
}

.leitner-subtext {
  font-size: 0.75rem;
  color: #94a3b8;
  margin-bottom: 12px;
  flex: 1;
}

:root:not([data-theme="dark"]) .leitner-subtext {
  color: #64748b;
}

.leitner-card-footer {
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

:root:not([data-theme="dark"]) .leitner-card-footer {
  border-top-color: #f1f5f9;
}

.leitner-exam-btn {
  width: 100%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 6px 10px;
  font-size: 0.78rem;
  font-weight: 700;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(255, 255, 255, 0.05);
  color: #e2e8f0;
  cursor: pointer;
  transition: all 0.2s ease;
}

:root:not([data-theme="dark"]) .leitner-exam-btn {
  background: #f8fafc;
  border-color: #e2e8f0;
  color: #334155;
}

.leitner-exam-btn:hover {
  background: rgba(124, 58, 237, 0.2);
  border-color: rgba(124, 58, 237, 0.4);
  color: #c084fc;
}

:root:not([data-theme="dark"]) .leitner-exam-btn:hover {
  background: #ede9fe;
  border-color: #c4b5fd;
  color: #6d28d9;
}

/* ─── 3. Controls & Filter Bar ─── */
.mistake-controls-bar {
  background: rgba(30, 41, 59, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  padding: 14px 18px;
  margin-bottom: 18px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  backdrop-filter: blur(12px);
}

:root:not([data-theme="dark"]) .mistake-controls-bar {
  background: #ffffff;
  border-color: #e2e8f0;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.04);
}

.mistake-filter-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.mistake-filter-group .filter-label {
  font-size: 0.85rem;
  font-weight: 700;
  color: #cbd5e1;
}

:root:not([data-theme="dark"]) .mistake-filter-group .filter-label {
  color: #475569;
}

.mistake-select {
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: #f8fafc;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: 10px;
  padding: 8px 14px;
  outline: none;
  cursor: pointer;
  transition: border-color 0.2s ease;
}

:root:not([data-theme="dark"]) .mistake-select {
  background: #ffffff;
  border-color: #cbd5e1;
  color: #0f172a;
}

.mistake-select:focus {
  border-color: #7c3aed;
  box-shadow: 0 0 0 2px rgba(124, 58, 237, 0.3);
}

.mistake-select option {
  background: #0f172a;
  color: #f8fafc;
}

:root:not([data-theme="dark"]) .mistake-select option {
  background: #ffffff;
  color: #0f172a;
}

.mistake-tabs {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.mistake-tab-btn {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: #94a3b8;
  font-size: 0.82rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

:root:not([data-theme="dark"]) .mistake-tab-btn {
  background: #f1f5f9;
  border-color: #e2e8f0;
  color: #475569;
}

.mistake-tab-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #f8fafc;
}

:root:not([data-theme="dark"]) .mistake-tab-btn:hover {
  background: #e2e8f0;
  color: #0f172a;
}

.mistake-tab-btn.active {
  background: linear-gradient(135deg, rgba(124, 58, 237, 0.3) 0%, rgba(99, 102, 241, 0.25) 100%);
  border-color: rgba(124, 58, 237, 0.5);
  color: #c084fc;
}

:root:not([data-theme="dark"]) .mistake-tab-btn.active {
  background: #ede9fe;
  border-color: #c4b5fd;
  color: #6d28d9;
}

.mistake-search-wrapper {
  position: relative;
  min-width: 240px;
}

.search-icon-inside {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: #64748b;
  pointer-events: none;
}

.mistake-search-input {
  width: 100%;
  padding: 8px 12px 8px 36px;
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 10px;
  color: #f8fafc;
  font-size: 0.85rem;
  outline: none;
  transition: border-color 0.2s ease;
}

:root:not([data-theme="dark"]) .mistake-search-input {
  background: #ffffff;
  border-color: #cbd5e1;
  color: #0f172a;
}

.mistake-search-input:focus {
  border-color: #7c3aed;
  box-shadow: 0 0 0 2px rgba(124, 58, 237, 0.3);
}

.mistake-search-input::placeholder {
  color: #64748b;
}

/* ─── 4. Action Strip ─── */
.mistake-actions-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  gap: 14px;
  flex-wrap: wrap;
}

.showing-count {
  font-size: 0.9rem;
  color: #475569;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.showing-count strong {
  color: #7c3aed;
  font-weight: 800;
}

[data-theme="dark"] .showing-count {
  color: #94a3b8;
}

[data-theme="dark"] .showing-count strong {
  color: #c084fc;
}

.filter-tag {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 6px;
  background: rgba(124, 58, 237, 0.15);
  border: 1px solid rgba(124, 58, 237, 0.3);
  color: #c084fc;
}

:root:not([data-theme="dark"]) .filter-tag {
  background: #ede9fe;
  border-color: #c4b5fd;
  color: #6d28d9;
}

.actions-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.action-btn-exam {
  background: linear-gradient(135deg, #0ea5e9 0%, #2563eb 100%);
  color: #ffffff;
  border: none;
  font-size: 0.88rem;
  font-weight: 700;
  padding: 9px 18px;
  border-radius: 12px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 4px 15px rgba(14, 165, 233, 0.35);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.action-btn-exam:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(14, 165, 233, 0.5);
}

.action-btn-practice {
  background: linear-gradient(135deg, #7c3aed 0%, #6366f1 100%);
  color: #ffffff;
  border: none;
  font-size: 0.88rem;
  font-weight: 700;
  padding: 9px 18px;
  border-radius: 12px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 4px 15px rgba(124, 58, 237, 0.35);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.action-btn-practice:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(124, 58, 237, 0.5);
}

.action-btn-clear {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid #cbd5e1;
  color: #475569;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

[data-theme="dark"] .action-btn-clear {
  background: rgba(15, 23, 42, 0.6);
  border-color: rgba(255, 255, 255, 0.08);
  color: #94a3b8;
}

.action-btn-clear:hover {
  background: rgba(239, 68, 68, 0.15);
  border-color: rgba(239, 68, 68, 0.3);
  color: #f87171;
}

/* ─── 5. Mistake Cards ─── */
.mistake-cards-list {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.mistake-item-card {
  background: rgba(30, 41, 59, 0.65);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 18px;
  padding: 24px;
  backdrop-filter: blur(12px);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  color: #f8fafc;
}

:root:not([data-theme="dark"]) .mistake-item-card {
  background: #ffffff;
  border-color: #e2e8f0;
  box-shadow: 0 4px 16px rgba(15, 23, 42, 0.06);
  color: #0f172a;
}

.mistake-item-card:hover {
  border-color: rgba(124, 58, 237, 0.35);
  box-shadow: 0 8px 25px -5px rgba(0, 0, 0, 0.3);
  transform: translateY(-2px);
}

:root:not([data-theme="dark"]) .mistake-item-card:hover {
  border-color: #c4b5fd;
  box-shadow: 0 8px 25px -5px rgba(15, 23, 42, 0.1);
}

.card-mastered {
  opacity: 0.85;
  border-color: rgba(16, 185, 129, 0.25);
}

:root:not([data-theme="dark"]) .card-mastered {
  border-color: #a7f3d0;
  background: #f0fdf4;
}

.mistake-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  gap: 12px;
  flex-wrap: wrap;
}

.mistake-badges {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.subject-pill {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 8px;
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(99, 102, 241, 0.3);
  color: #818cf8;
}

:root:not([data-theme="dark"]) .subject-pill {
  background: #e0e7ff;
  border-color: #c7d2fe;
  color: #4338ca;
}

.lesson-pill {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: #cbd5e1;
}

:root:not([data-theme="dark"]) .lesson-pill {
  background: #f1f5f9;
  border-color: #e2e8f0;
  color: #475569;
}

.format-pill {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 8px;
  background: rgba(245, 158, 11, 0.15);
  border: 1px solid rgba(245, 158, 11, 0.3);
  color: #fbbf24;
}

:root:not([data-theme="dark"]) .format-pill {
  background: #fef3c7;
  border-color: #fcd34d;
  color: #b45309;
}

.leitner-pill {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 6px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.leitner-pill.box-1 { background: rgba(239, 68, 68, 0.15); color: #f87171; border: 1px solid rgba(239, 68, 68, 0.3); }
.leitner-pill.box-2 { background: rgba(245, 158, 11, 0.15); color: #fbbf24; border: 1px solid rgba(245, 158, 11, 0.3); }
.leitner-pill.box-3 { background: rgba(59, 130, 246, 0.15); color: #60a5fa; border: 1px solid rgba(59, 130, 246, 0.3); }
.leitner-pill.box-4 { background: rgba(16, 185, 129, 0.15); color: #34d399; border: 1px solid rgba(16, 185, 129, 0.3); }

:root:not([data-theme="dark"]) .leitner-pill.box-1 { background: #fee2e2; color: #b91c1c; border-color: #fca5a5; }
:root:not([data-theme="dark"]) .leitner-pill.box-2 { background: #fef3c7; color: #b45309; border-color: #fcd34d; }
:root:not([data-theme="dark"]) .leitner-pill.box-3 { background: #dbeafe; color: #1d4ed8; border-color: #93c5fd; }
:root:not([data-theme="dark"]) .leitner-pill.box-4 { background: #d1fae5; color: #047857; border-color: #6ee7b7; }

.repeat-pill {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 8px;
  background: rgba(239, 68, 68, 0.15);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: #f87171;
}

:root:not([data-theme="dark"]) .repeat-pill {
  background: #fee2e2;
  border-color: #fca5a5;
  color: #b91c1c;
}

.status-badge-ok {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 8px;
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
}

:root:not([data-theme="dark"]) .status-badge-ok {
  background: #d1fae5;
  color: #047857;
}

.status-badge-need {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 8px;
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
}

:root:not([data-theme="dark"]) .status-badge-need {
  background: #fef3c7;
  color: #b45309;
}

.mistake-question-content {
  display: flex;
  gap: 12px;
  margin-bottom: 18px;
}

.q-index-badge {
  font-size: 0.85rem;
  font-weight: 800;
  color: #a855f7;
  padding-top: 2px;
}

.q-main-text {
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.6;
  color: #f1f5f9;
}

:root:not([data-theme="dark"]) .q-main-text {
  color: #0f172a;
}

/* ─── 6. Error Reason Bar & Categorization ─── */
.mistake-reason-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: 14px;
  margin-bottom: 14px;
  padding: 10px 14px;
  background: rgba(15, 23, 42, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 12px;
}

:root:not([data-theme="dark"]) .mistake-reason-bar {
  background: #f8fafc;
  border-color: #e2e8f0;
}

.reason-selector-group {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.reason-label {
  font-size: 0.78rem;
  font-weight: 700;
  color: #94a3b8;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

:root:not([data-theme="dark"]) .reason-label {
  color: #475569;
}

.reason-select {
  background: rgba(30, 41, 59, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #f8fafc;
  font-size: 0.8rem;
  font-weight: 600;
  padding: 5px 10px;
  border-radius: 8px;
  cursor: pointer;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

:root:not([data-theme="dark"]) .reason-select {
  background: #ffffff;
  border-color: #cbd5e1;
  color: #0f172a;
}

.reason-select:focus {
  border-color: #8b5cf6;
  box-shadow: 0 0 0 2px rgba(139, 92, 246, 0.25);
}

.reason-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid transparent;
}

.reason-pill.reason-reading_trap {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border-color: rgba(245, 158, 11, 0.3);
}

:root:not([data-theme="dark"]) .reason-pill.reason-reading_trap {
  background: #fef3c7;
  color: #b45309;
  border-color: #fcd34d;
}

.reason-pill.reason-calc_error {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border-color: rgba(239, 68, 68, 0.3);
}

:root:not([data-theme="dark"]) .reason-pill.reason-calc_error {
  background: #fee2e2;
  color: #b91c1c;
  border-color: #fca5a5;
}

.reason-pill.reason-forgot_formula {
  background: rgba(139, 92, 246, 0.15);
  color: #c084fc;
  border-color: rgba(139, 92, 246, 0.3);
}

:root:not([data-theme="dark"]) .reason-pill.reason-forgot_formula {
  background: #ede9fe;
  color: #6d28d9;
  border-color: #c4b5fd;
}

.reason-pill.reason-knowledge_gap {
  background: rgba(236, 72, 153, 0.15);
  color: #f472b6;
  border-color: rgba(236, 72, 153, 0.3);
}

:root:not([data-theme="dark"]) .reason-pill.reason-knowledge_gap {
  background: #fce7f3;
  color: #be185d;
  border-color: #fbcfe8;
}

/* ─── 7. Compare Box ─── */
.mistake-compare-box {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 14px;
  padding: 16px;
  margin-bottom: 16px;
}

:root:not([data-theme="dark"]) .mistake-compare-box {
  background: #f8fafc;
  border-color: #e2e8f0;
}

.compare-title {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: #94a3b8;
  margin-bottom: 12px;
}

:root:not([data-theme="dark"]) .compare-title {
  color: #64748b;
}

.mcq-compare-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.compare-opt-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-radius: 10px;
  background: rgba(30, 41, 59, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.92rem;
  transition: all 0.2s ease;
}

:root:not([data-theme="dark"]) .compare-opt-row {
  background: #ffffff;
  border-color: #e2e8f0;
}

.opt-letter {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 6px;
  font-weight: 800;
  font-size: 0.8rem;
  background: rgba(255, 255, 255, 0.06);
  color: #cbd5e1;
}

:root:not([data-theme="dark"]) .opt-letter {
  background: #f1f5f9;
  color: #475569;
}

.opt-text {
  flex: 1;
  color: #e2e8f0;
}

:root:not([data-theme="dark"]) .opt-text {
  color: #0f172a;
}

.opt-is-correct {
  background: rgba(16, 185, 129, 0.12) !important;
  border-color: rgba(16, 185, 129, 0.35) !important;
}

:root:not([data-theme="dark"]) .opt-is-correct {
  background: #d1fae5 !important;
  border-color: #6ee7b7 !important;
}

.opt-is-correct .opt-letter {
  background: #10b981;
  color: #ffffff;
}

.opt-user-wrong {
  background: rgba(239, 68, 68, 0.12) !important;
  border-color: rgba(239, 68, 68, 0.35) !important;
  text-decoration: line-through;
}

:root:not([data-theme="dark"]) .opt-user-wrong {
  background: #fee2e2 !important;
  border-color: #fca5a5 !important;
}

.opt-user-wrong .opt-letter {
  background: #ef4444;
  color: #ffffff;
}

.opt-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 6px;
}

.tag-correct {
  background: rgba(16, 185, 129, 0.2);
  color: #34d399;
}

:root:not([data-theme="dark"]) .tag-correct {
  background: #d1fae5;
  color: #047857;
}

.tag-wrong {
  background: rgba(239, 68, 68, 0.2);
  color: #f87171;
}

:root:not([data-theme="dark"]) .tag-wrong {
  background: #fee2e2;
  color: #b91c1c;
}

/* TF statements compare */
.tf-compare-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.tf-compare-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 12px;
  background: rgba(30, 41, 59, 0.4);
  border-radius: 8px;
  font-size: 0.88rem;
}

:root:not([data-theme="dark"]) .tf-compare-row {
  background: #ffffff;
  border: 1px solid #e2e8f0;
}

.tf-stmt-letter {
  font-weight: 700;
  color: #fbbf24;
}

:root:not([data-theme="dark"]) .tf-stmt-letter {
  color: #d97706;
}

.tf-stmt-text {
  flex: 1;
  color: #e2e8f0;
}

:root:not([data-theme="dark"]) .tf-stmt-text {
  color: #0f172a;
}

.tf-stmt-correct strong {
  color: #34d399;
}

:root:not([data-theme="dark"]) .tf-stmt-correct strong {
  color: #047857;
}

/* ─── 8. Explanation Box ─── */
.mistake-explanation-box {
  background: rgba(124, 58, 237, 0.08);
  border-left: 3px solid #7c3aed;
  border-radius: 0 12px 12px 0;
  padding: 14px 18px;
  margin-bottom: 16px;
}

:root:not([data-theme="dark"]) .mistake-explanation-box {
  background: #f5f3ff;
  border-left-color: #8b5cf6;
}

.exp-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  font-weight: 700;
  color: #c084fc;
  margin-bottom: 6px;
}

:root:not([data-theme="dark"]) .exp-title {
  color: #7c3aed;
}

.exp-content {
  font-size: 0.92rem;
  color: #cbd5e1;
  line-height: 1.6;
}

:root:not([data-theme="dark"]) .exp-content {
  color: #334155;
}

/* ─── 9. Footer & Leitner Action Buttons ─── */
.mistake-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  gap: 12px;
  flex-wrap: wrap;
}

:root:not([data-theme="dark"]) .mistake-card-footer {
  border-top-color: #f1f5f9;
}

.created-time {
  font-size: 0.78rem;
  color: #64748b;
}

:root:not([data-theme="dark"]) .created-time {
  color: #64748b;
}

.footer-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.review-promote-btn {
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.35);
  color: #34d399;
  font-size: 0.82rem;
  font-weight: 700;
  padding: 7px 12px;
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

:root:not([data-theme="dark"]) .review-promote-btn {
  background: #ecfdf5;
  border-color: #6ee7b7;
  color: #047857;
}

.review-promote-btn:hover {
  background: #10b981;
  color: #ffffff;
  transform: translateY(-1px);
}

.review-demote-btn {
  background: rgba(239, 68, 68, 0.15);
  border: 1px solid rgba(239, 68, 68, 0.35);
  color: #f87171;
  font-size: 0.82rem;
  font-weight: 700;
  padding: 7px 12px;
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

:root:not([data-theme="dark"]) .review-demote-btn {
  background: #fef2f2;
  border-color: #fca5a5;
  color: #b91c1c;
}

.review-demote-btn:hover {
  background: #ef4444;
  color: #ffffff;
  transform: translateY(-1px);
}

.retry-single-btn {
  background: rgba(245, 158, 11, 0.15);
  border: 1px solid rgba(245, 158, 11, 0.35);
  color: #fbbf24;
  font-size: 0.82rem;
  font-weight: 700;
  padding: 7px 14px;
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

:root:not([data-theme="dark"]) .retry-single-btn {
  background: #fef3c7;
  border-color: #fcd34d;
  color: #b45309;
}

.retry-single-btn:hover {
  background: #f59e0b;
  color: #000000;
}

.mark-mastered-btn {
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.35);
  color: #34d399;
  font-size: 0.82rem;
  font-weight: 700;
  padding: 7px 14px;
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

:root:not([data-theme="dark"]) .mark-mastered-btn {
  background: #d1fae5;
  border-color: #6ee7b7;
  color: #047857;
}

.mark-mastered-btn:hover {
  background: #10b981;
  color: #ffffff;
}

.remove-btn {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: #64748b;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

:root:not([data-theme="dark"]) .remove-btn {
  border-color: #e2e8f0;
  color: #94a3b8;
}

.remove-btn:hover {
  background: rgba(239, 68, 68, 0.15);
  border-color: rgba(239, 68, 68, 0.4);
  color: #f87171;
}

/* ─── 10. Empty State ─── */
.mistake-empty-state {
  text-align: center;
  padding: 60px 20px;
  background: rgba(30, 41, 59, 0.5);
  border: 1px dashed rgba(255, 255, 255, 0.12);
  border-radius: 20px;
}

:root:not([data-theme="dark"]) .mistake-empty-state {
  background: #ffffff;
  border-color: #cbd5e1;
}

.empty-icon {
  color: #10b981;
  margin-bottom: 16px;
}

.mistake-empty-state h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: #f8fafc;
  margin: 0 0 8px;
}

:root:not([data-theme="dark"]) .mistake-empty-state h3 {
  color: #0f172a;
}

.mistake-empty-state p {
  font-size: 0.95rem;
  color: #94a3b8;
  max-width: 480px;
  margin: 0 auto 20px;
  line-height: 1.5;
}

:root:not([data-theme="dark"]) .mistake-empty-state p {
  color: #64748b;
}

.empty-btn {
  background: linear-gradient(135deg, #7c3aed 0%, #6366f1 100%);
  color: #ffffff;
  border: none;
  font-size: 0.9rem;
  font-weight: 700;
  padding: 10px 22px;
  border-radius: 12px;
  cursor: pointer;
  transition: transform 0.2s ease;
}

.empty-btn:hover {
  transform: translateY(-2px);
}

/* ─── 11. Responsive Adjustments ─── */
@media (max-width: 900px) {
  .leitner-boxes-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .mistake-notebook-wrapper {
    padding: 16px 12px 60px;
  }
  .mistake-header-banner {
    padding: 20px 16px;
    gap: 16px;
  }
  .mistake-title {
    font-size: 1.4rem;
  }
  .mistake-stats-cards {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
  }
  .mistake-stat-card {
    min-width: 0;
  }
  .mistake-controls-bar {
    padding: 12px 14px;
    flex-direction: column;
    align-items: stretch;
  }
  .mistake-tabs {
    overflow-x: auto;
    padding-bottom: 4px;
    flex-wrap: nowrap;
  }
  .mistake-search-wrapper {
    min-width: 100%;
  }
  .mistake-actions-strip {
    flex-direction: column;
    align-items: stretch;
  }
  .actions-right {
    justify-content: stretch;
  }
  .actions-right button {
    flex: 1;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .leitner-boxes-grid {
    grid-template-columns: 1fr;
  }
}