/* ========================================================
   Maths30 — 30-Day NEET/JEE Calculation Trainer Stylesheet
   Clean, Minimal, Modern, Mobile-First, KaTeX-Optimized
   ======================================================== */

:root {
  /* Dark Theme Palette (Default) */
  --bg-main: #0b0f19;
  --bg-card: #131b2e;
  --bg-card-hover: #1b263f;
  --bg-glass: rgba(19, 27, 46, 0.85);
  --bg-subtle: #192238;
  --border-color: #23314f;
  --border-focus: #3b82f6;

  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --accent-primary: #3b82f6;
  --accent-primary-hover: #2563eb;
  --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  
  --success: #10b981;
  --success-bg: rgba(16, 185, 129, 0.12);
  --success-border: rgba(16, 185, 129, 0.3);

  --error: #ef4444;
  --error-bg: rgba(239, 68, 68, 0.12);
  --error-border: rgba(239, 68, 68, 0.3);

  --warning: #f59e0b;
  --warning-bg: rgba(245, 158, 11, 0.12);
  
  --star-gold: #fbbf24;
  
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.25);
  --shadow-md: 0 6px 16px rgba(0,0,0,0.35);
  --shadow-lg: 0 12px 28px rgba(0,0,0,0.45);
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;

  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="light"] {
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-glass: rgba(255, 255, 255, 0.9);
  --bg-subtle: #f1f5f9;
  --border-color: #e2e8f0;
  --border-focus: #2563eb;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;

  --accent-primary: #2563eb;
  --accent-primary-hover: #1d4ed8;
  --accent-gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);

  --success: #059669;
  --success-bg: #ecfdf5;
  --success-border: #a7f3d0;

  --error: #dc2626;
  --error-bg: #fef2f2;
  --error-border: #fecaca;

  --warning: #d97706;
  --warning-bg: #fffbeb;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 24px rgba(0,0,0,0.08);
}

/* Base Styles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color 0.25s ease, color 0.25s ease;
}

/* Header */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  padding: 0.75rem 1rem;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand-group {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  cursor: pointer;
  user-select: none;
}

.brand-icon {
  font-size: 1.8rem;
  line-height: 1;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.accent-text {
  color: var(--accent-primary);
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-badge {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

/* Nav Tabs */
.nav-tabs {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--bg-subtle);
  padding: 0.25rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.9rem;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition);
  position: relative;
}

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

.nav-btn.active {
  background: var(--bg-card);
  color: var(--accent-primary);
  box-shadow: var(--shadow-sm);
}

.counter-badge {
  font-size: 0.7rem;
  font-weight: 700;
  background: var(--accent-primary);
  color: #fff;
  padding: 0.1rem 0.4rem;
  border-radius: var(--radius-full);
  line-height: 1;
}

.counter-badge:empty, .counter-badge[data-count="0"] {
  display: none;
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.action-icon-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1rem;
  transition: var(--transition);
}

.action-icon-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-focus);
}

/* Main Container */
.app-main {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 1.5rem 1rem 4rem;
  flex: 1;
}

/* View Handling */
.view {
  display: none;
  animation: fadeIn 0.25s ease forwards;
}

.view.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Button Component */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  user-select: none;
}

.btn-sm {
  font-size: 0.8rem;
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  font-size: 1.05rem;
  padding: 0.85rem 1.6rem;
  border-radius: var(--radius-md);
}

.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.35);
}

.btn-primary:hover:not(:disabled) {
  opacity: 0.95;
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(59, 130, 246, 0.45);
}

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

.btn-secondary:hover:not(:disabled) {
  background: var(--bg-card-hover);
  border-color: var(--border-focus);
}

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

.btn-icon {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 600;
  transition: var(--transition);
}

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

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

.kbd-hint {
  font-size: 0.75rem;
  opacity: 0.7;
  font-family: var(--font-mono);
  background: rgba(0,0,0,0.2);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
}

/* ========================================================
   DASHBOARD STYLES
   ======================================================== */
.dashboard-hero {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  margin-bottom: 1.75rem;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.dashboard-hero::before {
  content: '';
  position: absolute;
  top: -50px;
  right: -50px;
  width: 220px;
  height: 220px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-primary);
  background: rgba(59, 130, 246, 0.1);
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
}

.hero-heading {
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 0.4rem;
  line-height: 1.2;
}

.hero-header-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1.5rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}

.hero-progress-pill {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  white-space: nowrap;
}

.hero-progress-pct {
  color: var(--accent-primary);
  background: rgba(59, 130, 246, 0.12);
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
}

.hero-subtext {
  color: var(--text-secondary);
  font-size: 0.95rem;
  max-width: 680px;
  margin-bottom: 0.5rem;
}

/* Resume Banner */
.resume-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.3);
  padding: 0.9rem 1.25rem;
  border-radius: var(--radius-md);
  margin-bottom: 1.25rem;
  gap: 1rem;
}

.resume-info {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.resume-icon {
  font-size: 1.6rem;
}

.resume-info strong {
  display: block;
  font-size: 0.95rem;
  color: var(--text-primary);
}

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

.resume-actions {
  display: flex;
  gap: 0.5rem;
}

/* Hero Progress Box */
.hero-progress-box {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
}

.progress-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.current-day-label {
  color: var(--text-primary);
}

.progress-percent {
  color: var(--accent-primary);
}

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

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

/* Global Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.15rem;
  display: flex;
  align-items: center;
  gap: 0.85rem;
  box-shadow: var(--shadow-sm);
}

.stat-icon-wrapper {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.stat-icon-wrapper.blue { background: rgba(59, 130, 246, 0.15); }
.stat-icon-wrapper.green { background: rgba(16, 185, 129, 0.15); }
.stat-icon-wrapper.purple { background: rgba(139, 92, 246, 0.15); }
.stat-icon-wrapper.orange { background: rgba(245, 158, 11, 0.15); }
.stat-icon-wrapper.teal { background: rgba(20, 184, 166, 0.15); }

.stat-data {
  display: flex;
  flex-direction: column;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.2;
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Exercises Section Header */
.section-header-row {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.section-title {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.section-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.tier-filter-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.chip {
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.chip:hover {
  color: var(--text-primary);
  border-color: var(--text-muted);
}

.chip.active {
  background: var(--accent-primary);
  color: #fff;
  border-color: var(--accent-primary);
}

/* Exercise Cards Grid */
.exercises-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.15rem;
}

.exercise-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.exercise-card:hover {
  transform: translateY(-2px);
  border-color: var(--border-focus);
  box-shadow: var(--shadow-md);
}

.exercise-card.locked {
  opacity: 0.65;
  filter: grayscale(0.2);
}

.ex-card-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.6rem;
}

.ex-id-pill {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-primary);
  background: rgba(59, 130, 246, 0.1);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
}

.tier-badge {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-full);
  background: var(--bg-subtle);
  color: var(--text-secondary);
}

.tier-badge.Foundation { color: #60a5fa; background: rgba(96, 165, 250, 0.1); }
.tier-badge.Basic { color: #34d399; background: rgba(52, 211, 153, 0.1); }
.tier-badge.Intermediate { color: #f59e0b; background: rgba(245, 158, 11, 0.1); }
.tier-badge.Upper-Int { color: #a78bfa; background: rgba(167, 139, 250, 0.1); }
.tier-badge.Advanced { color: #f43f5e; background: rgba(244, 63, 94, 0.1); }
.tier-badge.Exam-Level { color: #ec4899; background: rgba(236, 72, 153, 0.15); border: 1px solid rgba(236, 72, 153, 0.3); }

.ex-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.35rem;
}

.ex-card-sub {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.4;
  margin-bottom: 1rem;
  flex: 1;
}

.ex-card-stats {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 0.75rem;
  margin-bottom: 0.9rem;
  font-size: 0.75rem;
}

.ex-stat-item {
  display: flex;
  flex-direction: column;
}

.ex-stat-item span:first-child {
  color: var(--text-muted);
}

.ex-stat-item span:last-child {
  font-family: var(--font-mono);
  font-weight: 700;
}

.ex-card-btn {
  width: 100%;
}

/* ========================================================
   ACTIVE EXERCISE ARENA STYLES
   ======================================================== */
.arena-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.75rem 1rem;
  margin-bottom: 1rem;
  gap: 0.75rem;
}

.arena-header-left, .arena-header-right {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.arena-exercise-meta {
  display: flex;
  flex-direction: column;
}

.arena-ex-badge {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-primary);
}

.arena-ex-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.arena-header-center {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Stopwatch */
.stopwatch-container {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-full);
}

.stopwatch-icon {
  font-size: 1rem;
  animation: pulse 1.5s infinite;
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.15); }
  100% { transform: scale(1); }
}

.stopwatch-digits {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent-primary);
  letter-spacing: 0.05em;
}

.exercise-timer-pill {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.btn-arena-action {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.8rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background: var(--bg-subtle);
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.btn-arena-action:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
}

.btn-arena-action.bookmarked {
  background: rgba(251, 191, 36, 0.15);
  border-color: rgba(251, 191, 36, 0.4);
  color: var(--star-gold);
}

.btn-arena-action.bookmarked .star-icon {
  color: var(--star-gold);
}

.btn-pause:hover {
  border-color: var(--warning);
  color: var(--warning);
}

/* Arena Progress Bar */
.arena-progress-bar {
  margin-bottom: 0.75rem;
}

.section-tag-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.4rem;
}

.section-pill {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-primary);
  background: rgba(59, 130, 246, 0.1);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
}

.q-counter-text {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
}

/* Palette / Stepper (1 to 15 pills) */
.palette-container {
  margin-bottom: 1rem;
}

.palette-scroll {
  display: flex;
  gap: 0.35rem;
  overflow-x: auto;
  padding-bottom: 0.35rem;
  scrollbar-width: thin;
}

.palette-pill {
  flex: 0 0 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  cursor: pointer;
  position: relative;
  transition: var(--transition);
}

.palette-pill:hover {
  border-color: var(--text-primary);
  color: var(--text-primary);
}

.palette-pill.current {
  border-color: var(--accent-primary);
  background: rgba(59, 130, 246, 0.2);
  color: #fff;
  box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.4);
}

.palette-pill.correct {
  background: var(--success);
  border-color: var(--success);
  color: #fff;
}

.palette-pill.incorrect {
  background: var(--error);
  border-color: var(--error);
  color: #fff;
}

.palette-pill.has-star::after {
  content: '★';
  position: absolute;
  top: -4px;
  right: -3px;
  font-size: 0.6rem;
  color: var(--star-gold);
}

/* Arena Card Body */
.arena-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  margin-bottom: 2rem;
}

.question-box {
  margin-bottom: 2rem;
}

.q-header-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.q-type-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.btn-link-sm {
  background: transparent;
  border: none;
  color: var(--accent-primary);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
}

.btn-link-sm:hover {
  text-decoration: underline;
}

.hint-box {
  background: var(--warning-bg);
  border: 1px solid rgba(245, 158, 11, 0.3);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  color: var(--warning);
  font-size: 0.85rem;
  margin-bottom: 1rem;
}

.question-text {
  font-size: 1.35rem;
  font-weight: 600;
  line-height: 1.6;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

/* Math Content formatting */
.math-content .katex {
  font-size: 1.15em;
}

/* Answer Interactive Area */
.answer-interactive-area {
  margin-bottom: 1.5rem;
}

/* Numeric Form */
.numeric-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.numeric-input-group {
  display: flex;
  align-items: center;
  position: relative;
}

.numeric-input {
  width: 100%;
  background: var(--bg-subtle);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  font-family: var(--font-mono);
  font-size: 1.25rem;
  color: var(--text-primary);
  outline: none;
  transition: var(--transition);
}

.numeric-input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.25);
  background: var(--bg-card);
}

.unit-addon {
  position: absolute;
  right: 1.25rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 1rem;
  pointer-events: none;
}

/* MCQ Options */
.mcq-options-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 0.85rem;
  margin-bottom: 1.25rem;
}

.mcq-option-card {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.9rem 1.1rem;
  cursor: pointer;
  transition: var(--transition);
  user-select: none;
}

.mcq-option-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-focus);
}

.mcq-option-card.selected {
  background: rgba(59, 130, 246, 0.15);
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.3);
}

.option-key-badge {
  flex: 0 0 28px;
  height: 28px;
  border-radius: 6px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-secondary);
}

.mcq-option-card.selected .option-key-badge {
  background: var(--accent-primary);
  color: #fff;
  border-color: var(--accent-primary);
}

.option-text {
  font-size: 1rem;
  color: var(--text-primary);
}

.btn-submit {
  width: 100%;
  padding: 0.85rem;
  font-size: 1.05rem;
}

/* Explanation & Solution Box */
.explanation-box {
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-subtle);
  overflow: hidden;
  margin-bottom: 1.5rem;
  animation: fadeIn 0.2s ease;
}

.feedback-banner {
  padding: 0.75rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.feedback-banner.correct {
  background: var(--success-bg);
  color: var(--success);
  border-bottom: 1px solid var(--success-border);
}

.feedback-banner.incorrect {
  background: var(--error-bg);
  color: var(--error);
  border-bottom: 1px solid var(--error-border);
}

.solution-details {
  padding: 1.25rem;
}

.solution-answers-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  margin-bottom: 1rem;
  padding-bottom: 0.9rem;
  border-bottom: 1px solid var(--border-color);
}

.ans-block {
  display: flex;
  flex-direction: column;
}

.ans-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 600;
}

.ans-val {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
}

.ans-block.user-ans .ans-val {
  color: var(--text-primary);
}

.ans-block.correct-ans .ans-val {
  color: var(--success);
}

.ans-block.time-ans .ans-val {
  color: var(--accent-primary);
}

.step-by-step-box {
  margin-bottom: 1rem;
}

.step-header {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
}

.step-content {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--text-primary);
}

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

/* Arena Footer */
.arena-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 1.5rem;
  gap: 1rem;
}

.footer-center-note {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ========================================================
   RESULTS VIEW STYLES
   ======================================================== */
.results-container {
  max-width: 800px;
  margin: 0 auto;
}

.results-hero {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-md);
}

.results-badge {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--success);
  background: var(--success-bg);
  border: 1px solid var(--success-border);
  padding: 0.3rem 0.8rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
}

.results-title {
  font-size: 1.85rem;
  font-weight: 800;
  margin-bottom: 0.25rem;
}

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

.results-score-row {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 2rem;
}

.score-circle {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 140px;
  height: 140px;
  border-radius: var(--radius-full);
  background: var(--bg-subtle);
  border: 4px solid var(--accent-primary);
  box-shadow: 0 0 20px rgba(59, 130, 246, 0.2);
}

.score-num {
  font-family: var(--font-mono);
  font-size: 1.75rem;
  font-weight: 800;
  line-height: 1.1;
}

.score-pct {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-primary);
}

.score-quick-metrics {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  text-align: left;
}

.metric-pill {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  padding: 0.6rem 1rem;
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
}

.metric-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  font-weight: 600;
}

.metric-val {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
}

/* Breakdown Grid */
.results-section-breakdown {
  margin-bottom: 1.5rem;
}

.sub-heading {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.85rem;
}

.breakdown-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.five-sections-grid {
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
}

.breakdown-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
}

.sec-name {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.sec-score {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent-primary);
  margin-bottom: 0.5rem;
}

.mini-progress {
  height: 6px;
  background: var(--border-color);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.mini-bar {
  height: 100%;
  background: var(--accent-gradient);
  border-radius: var(--radius-full);
}

/* Insights Cards */
.insights-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.insight-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.insight-icon {
  font-size: 1.5rem;
}

.insight-label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.insight-value {
  font-size: 0.95rem;
  font-weight: 700;
}

/* Results Review Panels */
.results-review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin-bottom: 1.5rem;
}

.panel-header {
  margin-bottom: 0.85rem;
}

.panel-title {
  font-size: 1rem;
  font-weight: 700;
}

.review-items-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.review-item {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
}

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

/* ========================================================
   ANALYTICS & GRAPH VIEW
   ======================================================== */
.analytics-container {
  max-width: 1000px;
  margin: 0 auto;
}

.analytics-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.metric-toggles {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  background: var(--bg-card);
  padding: 0.3rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.toggle-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.toggle-btn:hover {
  color: var(--text-primary);
}

.toggle-btn.active {
  background: var(--accent-primary);
  color: #fff;
}

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

.graph-meta-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.graph-chart-title {
  font-size: 1.1rem;
  font-weight: 700;
}

.graph-hint-badge {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.chart-wrapper {
  position: relative;
  width: 100%;
  height: 380px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

#canvas-progress-chart {
  width: 100%;
  height: 100%;
  display: block;
}

.empty-chart-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  background: rgba(11, 15, 25, 0.85);
  color: var(--text-secondary);
}

.empty-icon {
  font-size: 2.5rem;
}

.graph-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  margin-top: 1rem;
  font-size: 0.8rem;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.legend-color-box {
  width: 12px;
  height: 12px;
  border-radius: 3px;
}

.analytics-summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

/* ========================================================
   MISTAKES & BOOKMARKS PAGE
   ======================================================== */
.page-container {
  max-width: 900px;
  margin: 0 auto;
}

.page-header-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.filter-pills {
  display: flex;
  gap: 0.4rem;
}

.badge-pill {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--star-gold);
  background: rgba(251, 191, 36, 0.15);
  padding: 0.3rem 0.8rem;
  border-radius: var(--radius-full);
}

.items-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.empty-state-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3rem 1.5rem;
  text-align: center;
  color: var(--text-secondary);
}

.empty-state-icon {
  font-size: 3rem;
  margin-bottom: 0.75rem;
}

.empty-state-text {
  font-size: 1rem;
  max-width: 400px;
  margin: 0 auto 1.25rem;
}

/* Mistake Card */
.mistake-card, .bookmark-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.card-meta-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
}

.meta-tags {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.tag-ex {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-primary);
}

.tag-sec {
  font-size: 0.7rem;
  font-weight: 600;
  background: var(--bg-subtle);
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
}

.tag-time {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.card-question-text {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 1rem;
  line-height: 1.5;
}

.mistake-answers-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1rem;
}

.mistake-retry-box {
  display: flex;
  gap: 0.75rem;
  align-items: center;
  margin-top: 0.75rem;
}

.mistake-input {
  flex: 1;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.55rem 0.85rem;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.95rem;
}

/* ========================================================
   MODALS
   ======================================================== */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  animation: fadeIn 0.2s ease;
}

.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  max-width: 480px;
  width: 100%;
  box-shadow: var(--shadow-lg);
}

.pause-modal {
  text-align: center;
}

.pause-icon-big {
  font-size: 3.5rem;
  margin-bottom: 0.5rem;
}

.modal-title {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.4rem;
}

.modal-text {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

.pause-time-box {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.85rem;
  margin-bottom: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

.pause-time-box strong {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--accent-primary);
}

.modal-actions-row {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

/* Settings Modal */
.settings-modal .modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.btn-close {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.25rem;
  cursor: pointer;
}

.btn-close:hover {
  color: var(--text-primary);
}

.settings-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.setting-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.setting-item p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.setting-item.danger-zone {
  border-bottom: none;
  padding-top: 0.5rem;
}

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

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

.toggle-slider {
  position: absolute;
  cursor: pointer;
  inset: 0;
  background-color: var(--border-color);
  transition: 0.3s;
  border-radius: 34px;
}

.toggle-slider:before {
  position: absolute;
  content: "";
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: 0.3s;
  border-radius: 50%;
}

input:checked + .toggle-slider {
  background-color: var(--accent-primary);
}

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

/* Toast Notifications */
.toast-container {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2000;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  pointer-events: none;
}

.toast {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.25s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes toastIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ========================================================
   RESPONSIVE ADJUSTMENTS
   ======================================================== */
@media (max-width: 768px) {
  .app-header {
    padding: 0.5rem 0.75rem;
  }

  .brand-badge {
    display: none;
  }

  .nav-tabs {
    order: 3;
    width: 100%;
    justify-content: space-around;
  }

  .header-container {
    flex-wrap: wrap;
  }

  .app-main {
    padding: 1rem 0.75rem 5rem;
  }

  .hero-heading {
    font-size: 1.4rem;
  }

  .dashboard-hero {
    padding: 1.25rem;
  }

  .arena-card {
    padding: 1.25rem;
  }

  .question-text {
    font-size: 1.15rem;
  }

  .insights-grid {
    grid-template-columns: 1fr;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .stats-grid .stat-card:last-child {
    grid-column: span 2;
  }
}

@media (max-width: 480px) {
  .nav-btn .nav-label {
    display: none;
  }

  .nav-btn {
    padding: 0.5rem 0.75rem;
    font-size: 1.1rem;
  }

  .arena-header-center {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
  }

  .exercise-timer-pill {
    display: none;
  }

  .arena-header-right span:not(.star-icon) {
    display: none;
  }

  .btn-arena-action {
    padding: 0.45rem 0.55rem;
  }
}