/* ==========================================================================
   NPTEL Software Engineering Mastery - Modern Stylesheet
   ========================================================================== */

:root {
  /* Dark Theme Colors (Default) */
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --bg-card: rgba(30, 41, 59, 0.85);
  --bg-code: #090d16;
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --border-color: rgba(255, 255, 255, 0.08);
  --border-focus: #3b82f6;

  /* Leitner Box Colors */
  --b1-color: #ef4444; /* Learning (Red) */
  --b2-color: #f59e0b; /* Reviewing (Amber) */
  --b3-color: #3b82f6; /* Developing (Blue) */
  --b4-color: #06b6d4; /* Retaining (Cyan) */
  --b5-color: #10b981; /* Mastered (Green) */

  /* Functional Accents */
  --accent-primary: #3b82f6;
  --accent-hover: #2563eb;
  --success-color: #10b981;
  --danger-color: #ef4444;
  --warning-color: #f59e0b;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 15px rgba(59, 130, 246, 0.3);

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

body.light-theme {
  --bg-primary: #f1f5f9;
  --bg-secondary: #ffffff;
  --bg-tertiary: #e2e8f0;
  --bg-card: rgba(255, 255, 255, 0.95);
  --bg-code: #1e293b;
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  
  --border-color: rgba(0, 0, 0, 0.1);
  --border-focus: #2563eb;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
}

/* ==========================================================================
   Base Styles & Reset
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.25s ease, color 0.25s ease;
}

/* ==========================================================================
   Header Layout
   ========================================================================== */
.app-header {
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  font-size: 1.8rem;
}

.logo-text h1 {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.logo-text .sub-title {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* Header Center: Live Leitner Progress */
.header-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  flex: 1;
  max-width: 480px;
}

.mastery-summary {
  width: 100%;
}

.mastery-info {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: 0.8rem;
  margin-bottom: 4px;
}

.mastery-label {
  color: var(--text-secondary);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.7rem;
}

.mastery-value {
  font-weight: 700;
  color: var(--b5-color);
  font-size: 0.9rem;
}

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

.progress-track {
  width: 100%;
  height: 8px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--b1-color), var(--b3-color), var(--b5-color));
  border-radius: var(--radius-full);
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Live Box Chips */
.box-chips {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  justify-content: center;
}

.box-chip {
  font-size: 0.72rem;
  padding: 2px 7px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-tertiary);
  color: var(--text-secondary);
  border-left: 3px solid;
  font-weight: 500;
}

.box-chip.b1 { border-color: var(--b1-color); }
.box-chip.b2 { border-color: var(--b2-color); }
.box-chip.b3 { border-color: var(--b3-color); }
.box-chip.b4 { border-color: var(--b4-color); }
.box-chip.b5 { border-color: var(--b5-color); }

.box-chip strong {
  color: var(--text-primary);
  font-weight: 700;
}

/* Header Right */
.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.streak-badge {
  display: flex;
  align-items: center;
  gap: 4px;
  background-color: rgba(245, 158, 11, 0.15);
  color: #f59e0b;
  border: 1px solid rgba(245, 158, 11, 0.3);
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
}

.icon-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background-color 0.2s, border-color 0.2s;
}

.icon-btn:hover {
  background-color: var(--bg-tertiary);
  border-color: var(--text-muted);
}

/* ==========================================================================
   Navigation Tabs
   ========================================================================== */
.nav-tabs {
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 0 24px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
}

.nav-tab {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 10px 16px;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
  white-space: nowrap;
}

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

.nav-tab.active {
  color: var(--accent-primary);
  border-bottom-color: var(--accent-primary);
}

/* ==========================================================================
   Main Content Views
   ========================================================================== */
.app-main {
  flex: 1;
  max-width: 960px;
  width: 100%;
  margin: 0 auto;
  padding: 24px 16px;
  overflow-y: auto;
}

.view-panel {
  display: none;
  animation: fadeIn 0.2s ease-in-out;
}

.view-panel.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ==========================================================================
   Quiz / Memorization Card
   ========================================================================== */
.quiz-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(12px);
  position: relative;
}

.card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: 10px;
}

.meta-left, .meta-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.q-badge {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.box-badge {
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.box-badge.b1 { background-color: rgba(239, 68, 68, 0.15); color: var(--b1-color); border: 1px solid var(--b1-color); }
.box-badge.b2 { background-color: rgba(245, 158, 11, 0.15); color: var(--b2-color); border: 1px solid var(--b2-color); }
.box-badge.b3 { background-color: rgba(59, 130, 246, 0.15); color: var(--b3-color); border: 1px solid var(--b3-color); }
.box-badge.b4 { background-color: rgba(6, 182, 212, 0.15); color: var(--b4-color); border: 1px solid var(--b4-color); }
.box-badge.b5 { background-color: rgba(16, 185, 129, 0.15); color: var(--b5-color); border: 1px solid var(--b5-color); }

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

.queue-info strong {
  color: var(--text-primary);
}

.pill-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.2s;
}

.pill-btn:hover {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
}

/* Question Title */
.question-title {
  font-size: 1.22rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--text-primary);
  margin-bottom: 20px;
}

/* Code Snippet Wrapper */
.q-code-wrapper {
  background-color: var(--bg-code);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md);
  margin: 16px 0 20px 0;
  overflow: hidden;
}

.code-header {
  background-color: rgba(255, 255, 255, 0.04);
  padding: 8px 14px;
  display: flex;
  align-items: center;
  gap: 6px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.code-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
}
.code-dot.red { background-color: #ef4444; }
.code-dot.yellow { background-color: #f59e0b; }
.code-dot.green { background-color: #10b981; }

.code-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-left: 6px;
}

.q-code-wrapper pre {
  padding: 14px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.5;
  color: #38bdf8;
}

/* Image / Diagram Container */
.q-image-wrapper {
  margin: 16px 0 24px 0;
  text-align: center;
}

.image-box {
  display: inline-block;
  background-color: #ffffff;
  padding: 12px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  max-width: 100%;
}

.image-box img {
  max-width: 100%;
  max-height: 380px;
  height: auto;
  border-radius: var(--radius-sm);
  display: block;
}

.image-caption {
  display: block;
  font-size: 0.75rem;
  color: #64748b;
  margin-top: 6px;
  font-weight: 600;
}

/* Table Wrapper */
.q-table-wrapper {
  margin: 16px 0 20px 0;
  overflow-x: auto;
}

.q-table-wrapper table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.q-table-wrapper th, .q-table-wrapper td {
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.q-table-wrapper th {
  background-color: var(--bg-tertiary);
  font-weight: 700;
  color: var(--text-primary);
}

/* ==========================================================================
   Options Grid & Interactive Buttons
   ========================================================================== */
.options-grid {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 20px;
}

.option-btn {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.98rem;
  text-align: left;
  display: flex;
  align-items: flex-start;
  gap: 14px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--shadow-sm);
  width: 100%;
}

.option-btn:hover:not(:disabled) {
  background-color: var(--bg-tertiary);
  border-color: var(--accent-primary);
  transform: translateY(-1px);
}

.option-btn:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 2px;
}

.opt-key {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-weight: 700;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: all 0.2s;
}

.opt-text {
  flex: 1;
  line-height: 1.45;
}

/* Option States: Correct / Incorrect / Dimmed */
.option-btn.correct {
  background-color: rgba(16, 185, 129, 0.15) !important;
  border-color: var(--success-color) !important;
  color: #a7f3d0 !important;
}

.option-btn.correct .opt-key {
  background-color: var(--success-color);
  color: #ffffff;
  border-color: var(--success-color);
}

.option-btn.incorrect {
  background-color: rgba(239, 68, 68, 0.15) !important;
  border-color: var(--danger-color) !important;
  color: #fca5a5 !important;
}

.option-btn.incorrect .opt-key {
  background-color: var(--danger-color);
  color: #ffffff;
  border-color: var(--danger-color);
}

.option-btn.dimmed {
  opacity: 0.45;
  cursor: default;
}

/* Active Recall Curtain */
.ar-curtain {
  background-color: var(--bg-secondary);
  border: 1px dashed var(--accent-primary);
  border-radius: var(--radius-md);
  padding: 32px 20px;
  text-align: center;
  margin-top: 16px;
}

.ar-hint {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 16px;
}

/* ==========================================================================
   Feedback Panel (After Answering)
   ========================================================================== */
.feedback-panel {
  margin-top: 24px;
  padding: 20px;
  border-radius: var(--radius-md);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  animation: slideUp 0.25s ease-out;
}

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

.feedback-banner {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
}

.fb-icon {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 700;
  flex-shrink: 0;
}

.feedback-panel.success .fb-icon {
  background-color: rgba(16, 185, 129, 0.2);
  color: var(--success-color);
}

.feedback-panel.success #feedback-title {
  color: var(--success-color);
}

.feedback-panel.danger .fb-icon {
  background-color: rgba(239, 68, 68, 0.2);
  color: var(--danger-color);
}

.feedback-panel.danger #feedback-title {
  color: var(--danger-color);
}

.fb-text-group h3 {
  font-size: 1.1rem;
  font-weight: 700;
}

.fb-text-group p {
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.answer-detail {
  padding: 12px 14px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  margin-bottom: 16px;
}

.highlight-answer {
  color: var(--success-color);
  font-weight: 600;
  margin-left: 6px;
}

.feedback-actions {
  display: flex;
  justify-content: flex-end;
}

/* Buttons */
.btn {
  font-family: inherit;
  font-weight: 600;
  font-size: 0.92rem;
  padding: 10px 18px;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.2s;
}

.primary-btn {
  background-color: var(--accent-primary);
  color: #ffffff;
}

.primary-btn:hover {
  background-color: var(--accent-hover);
  box-shadow: var(--shadow-glow);
}

.large-btn {
  padding: 12px 24px;
  font-size: 1rem;
}

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

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

.warning-btn {
  background-color: var(--warning-color);
  color: #1e293b;
}

.danger-btn {
  background-color: var(--danger-color);
  color: #ffffff;
}

.danger-btn:hover {
  opacity: 0.9;
}

.shortcut-tag {
  font-size: 0.75rem;
  opacity: 0.8;
  font-weight: 400;
}

/* ==========================================================================
   Practice by Box View
   ========================================================================== */
.filter-header-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.filter-header-card h2 {
  font-size: 1.3rem;
  margin-bottom: 6px;
}

.filter-header-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 24px;
}

.box-selection-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
}

.box-select-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px 14px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  border-top: 4px solid;
}

.box-select-card.b1 { border-color: var(--b1-color); }
.box-select-card.b2 { border-color: var(--b2-color); }
.box-select-card.b3 { border-color: var(--b3-color); }
.box-select-card.b4 { border-color: var(--b4-color); }
.box-select-card.b5 { border-color: var(--b5-color); }

.box-number {
  font-size: 1.15rem;
  font-weight: 800;
}

.box-title {
  font-size: 0.78rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.box-qty {
  font-size: 0.88rem;
  font-weight: 700;
  margin: 6px 0 10px 0;
}

.drill-btn {
  width: 100%;
  justify-content: center;
  padding: 8px 12px;
  font-size: 0.85rem;
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
}

.drill-btn:hover {
  background-color: var(--accent-primary);
  color: #ffffff;
}

/* ==========================================================================
   Exam View
   ========================================================================== */
.exam-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.exam-card h2 {
  font-size: 1.4rem;
  margin-bottom: 8px;
}

.exam-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 24px;
}

.config-group {
  margin-bottom: 24px;
}

.config-group label {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 10px;
}

.pill-group {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.pill-option {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 10px 16px;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-size: 0.88rem;
  font-weight: 600;
  transition: all 0.2s;
}

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

.checkbox-label {
  display: flex !important;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  color: var(--text-primary) !important;
}

.exam-top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 20px;
  margin-bottom: 16px;
}

.exam-timer {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--warning-color);
}

.exam-palette {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 18px;
  padding: 16px;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
}

.palette-btn {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s;
}

.palette-btn.current {
  outline: 2px solid var(--accent-primary);
}

.palette-btn.answered {
  background-color: var(--accent-primary);
  color: #ffffff;
}

.exam-nav-bar {
  display: flex;
  justify-content: space-between;
  margin-top: 24px;
}

/* Exam Result Card */
.exam-result-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  text-align: center;
}

.score-circle-container {
  display: flex;
  justify-content: center;
  margin: 24px 0;
}

.score-circle {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  border: 8px solid var(--accent-primary);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

#exam-score-percent {
  font-size: 2rem;
  font-weight: 800;
}

.score-sub {
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-transform: uppercase;
}

.exam-score-stats {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

.stat-pill {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 8px 16px;
  border-radius: var(--radius-full);
  font-size: 0.9rem;
}

.stat-pill.green strong { color: var(--success-color); }
.stat-pill.red strong { color: var(--danger-color); }
.stat-pill.yellow strong { color: var(--warning-color); }

.exam-review-list {
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 24px 0;
  max-height: 480px;
  overflow-y: auto;
  padding-right: 6px;
}

.review-item {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  border-left: 4px solid;
}

.review-item.correct { border-left-color: var(--success-color); }
.review-item.incorrect { border-left-color: var(--danger-color); }
.review-item.unanswered { border-left-color: var(--warning-color); }

/* ==========================================================================
   Browse All View
   ========================================================================== */
.browse-header-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  margin-bottom: 18px;
}

.browse-controls {
  display: flex;
  gap: 12px;
  margin-top: 14px;
  flex-wrap: wrap;
}

.search-input {
  flex: 1;
  min-width: 240px;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 10px 14px;
  color: var(--text-primary);
  font-size: 0.92rem;
  outline: none;
}

.search-input:focus {
  border-color: var(--accent-primary);
}

.select-filter {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 10px 14px;
  color: var(--text-primary);
  font-size: 0.92rem;
  outline: none;
}

.browse-list-container {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.browse-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  transition: border-color 0.2s;
}

.browse-card:hover {
  border-color: rgba(255, 255, 255, 0.2);
}

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

.browse-q-title {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.browse-options {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  margin-top: 10px;
}

.browse-opt {
  font-size: 0.9rem;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
}

.browse-opt.is-answer {
  background-color: rgba(16, 185, 129, 0.15);
  color: #a7f3d0;
  font-weight: 600;
  border-left: 3px solid var(--success-color);
}

/* ==========================================================================
   Stats View
   ========================================================================== */
.stats-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.stats-overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin: 20px 0 32px 0;
}

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

.widget-label {
  font-size: 0.78rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  font-weight: 600;
}

.widget-value {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--text-primary);
  margin: 6px 0;
}

.widget-sub {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.chart-section {
  margin-bottom: 32px;
}

.chart-section h3, .weakest-questions-section h3, .danger-zone h3 {
  font-size: 1.1rem;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.box-distribution-bars {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.bar-row {
  display: flex;
  align-items: center;
  gap: 14px;
}

.bar-label {
  width: 140px;
  font-size: 0.85rem;
  font-weight: 600;
}

.b1-text { color: var(--b1-color); }
.b2-text { color: var(--b2-color); }
.b3-text { color: var(--b3-color); }
.b4-text { color: var(--b4-color); }
.b5-text { color: var(--b5-color); }

.bar-track {
  flex: 1;
  height: 12px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.bar-fill {
  height: 100%;
  border-radius: var(--radius-full);
  transition: width 0.4s ease;
}

.bar-fill.b1 { background-color: var(--b1-color); }
.bar-fill.b2 { background-color: var(--b2-color); }
.bar-fill.b3 { background-color: var(--b3-color); }
.bar-fill.b4 { background-color: var(--b4-color); }
.bar-fill.b5 { background-color: var(--b5-color); }

.bar-val {
  width: 85px;
  text-align: right;
  font-size: 0.82rem;
  color: var(--text-secondary);
  font-weight: 600;
}

.weakest-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 32px;
}

.weak-item {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.88rem;
}

.danger-zone {
  background-color: rgba(239, 68, 68, 0.05);
  border: 1px solid rgba(239, 68, 68, 0.2);
  border-radius: var(--radius-md);
  padding: 20px;
}

.danger-zone p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 14px;
}

/* ==========================================================================
   Footer Legend
   ========================================================================== */
.app-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 10px 24px;
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
}

.shortcut-legend {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

kbd {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 2px 6px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-primary);
}

/* Utilities */
.hidden {
  display: none !important;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .app-header {
    flex-direction: column;
    align-items: stretch;
    padding: 12px 16px;
    gap: 12px;
  }
  .header-left, .header-right {
    justify-content: space-between;
  }
  .nav-tabs {
    padding: 0 12px;
  }
  .quiz-card {
    padding: 18px 16px;
  }
  .bar-label {
    width: 100px;
  }
}