/* ============================================
   LinguaDojo Custom Styles
   Design System: Educational Focus
   ============================================ */

/* CSS Variables */
:root {
  /* Primary Colors */
  --primary: #1e40af;
  --primary-hover: #1e3a8a;
  --success: #059669;
  --success-hover: #047857;
  --danger: #dc2626;
  --danger-hover: #b91c1c;
  --warning: #ea580c;
  --info: #0284c7;
  --accent: #f59e0b;

  /* Neutral Slate Scale */
  --slate-900: #0f172a;
  --slate-800: #1e293b;
  --slate-700: #334155;
  --slate-600: #475569;
  --slate-500: #64748b;
  --slate-400: #94a3b8;
  --slate-300: #cbd5e1;
  --slate-200: #e2e8f0;
  --slate-100: #f1f5f9;
  --slate-50: #f8fafc;

  /* Semantic Surface & Text (theme-overridable) */
  --bg-body: var(--slate-50);
  --bg-surface: #ffffff;
  --bg-surface-hover: var(--slate-50);
  --bg-muted: var(--slate-100);
  --text-primary: var(--slate-900);
  --text-secondary: var(--slate-600);
  --text-muted: var(--slate-500);
  --border-default: var(--slate-200);
  --border-strong: var(--slate-300);
  --focus-ring: rgba(30, 64, 175, 0.1);

  /* Semantic Backgrounds */
  --success-bg: #d1fae5;
  --danger-bg: #fee2e2;
  --warning-bg: #fed7aa;
  --info-bg: #e0f2fe;
  --selected-bg: #dbeafe;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 20px 60px rgba(15, 23, 42, 0.15);

  /* Transitions */
  --transition-fast: all 0.15s ease;
  --transition-base: all 0.2s ease;
  --transition-slow: all 0.3s ease;
  --theme-transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

/* ============================================
   Base & Global
   ============================================ */
body {
  background: var(--bg-body);
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.5;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 600;
  line-height: 1.2;
}

h1 { font-size: 28px; font-weight: 700; }
h2 { font-size: 24px; }
h3 { font-size: 20px; }

a {
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition-fast);
}

a:hover {
  text-decoration: underline;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  border-radius: 8px;
  padding: 12px 24px;
  font-size: 16px;
  font-weight: 600;
  transition: var(--transition-base);
  border: none;
}

.btn:active {
  transform: translateY(0);
}

.btn:disabled {
  background: var(--border-strong);
  cursor: not-allowed;
  opacity: 0.6;
}

/* Primary Button */
.btn-primary {
  background: var(--primary);
  border-color: var(--primary);
}

.btn-primary:hover,
.btn-primary:focus {
  background: var(--primary-hover);
  border-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px var(--focus-ring);
}

/* Success Button */
.btn-success {
  background: var(--success);
  border-color: var(--success);
}

.btn-success:hover,
.btn-success:focus {
  background: var(--success-hover);
  border-color: var(--success-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(5, 150, 105, 0.25);
}

/* Secondary Button */
.btn-secondary {
  background: var(--bg-muted);
  color: var(--text-secondary);
  border: 1px solid var(--border-default);
}

.btn-secondary:hover {
  background: var(--border-default);
  color: var(--text-secondary);
}

/* Danger Button */
.btn-danger {
  background: var(--danger);
  border-color: var(--danger);
}

.btn-danger:hover,
.btn-danger:focus {
  background: var(--danger-hover);
  border-color: var(--danger-hover);
  box-shadow: 0 4px 12px rgba(220, 38, 38, 0.25);
}

/* Icon Button */
.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: 50%;
  background: transparent;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn-icon:hover {
  background: var(--bg-muted);
}

.btn-icon:active {
  background: var(--border-default);
}

/* ============================================
   Cards
   ============================================ */
.card {
  background: var(--bg-surface);
  border-radius: 12px;
  border: 1px solid var(--border-default);
  box-shadow: var(--shadow-sm);
  transition: var(--transition-base);
}

/* Question Card */
.question-card {
  background: var(--bg-surface);
  border: 2px solid var(--border-default);
  border-radius: 12px;
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.question-card:hover {
  box-shadow: var(--shadow-md);
}

/* Answer Option */
.answer-option {
  background: var(--bg-surface);
  border: 2px solid var(--border-strong);
  border-radius: 8px;
  padding: 16px;
  cursor: pointer;
  transition: var(--transition-fast);
  margin-bottom: 12px;
}

.answer-option:hover {
  border-color: var(--slate-400);
  background: var(--bg-surface-hover);
}

.answer-option.selected {
  border-color: var(--primary);
  border-width: 3px;
  background: var(--selected-bg);
  animation: scaleIn 0.15s ease;
}

.answer-option.correct {
  border-left: 4px solid var(--success);
  background: var(--success-bg);
}

.answer-option.incorrect {
  border-left: 4px solid var(--danger);
  background: var(--danger-bg);
}

/* Dashboard Card */
.dashboard-card {
  background: var(--bg-surface);
  border-radius: 8px;
  padding: 20px;
}

/* Audio Player Card */
.audio-player {
  background: var(--bg-body);
  border: 1px solid var(--border-default);
  border-radius: 12px;
  padding: 20px;
}

/* ============================================
   Forms
   ============================================ */
.form-control {
  background: var(--bg-surface);
  border: 2px solid var(--border-strong);
  border-radius: 8px;
  padding: 12px 16px;
  font-size: 16px;
  color: var(--text-primary);
  transition: var(--transition-fast);
}

.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--focus-ring);
}

.form-select {
  background-color: var(--bg-surface);
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.form-control.is-invalid {
  border-color: var(--danger);
}

.form-control.is-invalid:focus {
  box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.1);
}

/* Seamless Input Groups */
.input-group-text {
  background: var(--bg-surface);
  border: 2px solid var(--border-strong);
  border-right: none;
  color: var(--text-muted);
}

.form-control.border-start-0 {
  border-left: none;
}

.input-group:focus-within .input-group-text,
.input-group:focus-within .form-control {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--focus-ring);
}

/* Radio & Checkbox */
.form-check-input {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border-strong);
}

.form-check-input:checked {
  background-color: var(--primary);
  border-color: var(--primary);
}

.form-check-input:focus {
  box-shadow: 0 0 0 3px var(--focus-ring);
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-default);
  padding: 16px 0;
  box-shadow: var(--shadow-sm);
}

.nav-link {
  color: var(--text-muted);
  font-size: 16px;
  font-weight: 500;
  padding: 8px 16px;
  border-bottom: 3px solid transparent;
  transition: var(--transition-base);
}

.nav-link:hover {
  color: var(--text-secondary);
}

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

/* Breadcrumb */
.breadcrumb {
  background: transparent;
  font-size: 14px;
  margin-bottom: 0;
}

.breadcrumb-item a {
  color: var(--text-secondary);
}

.breadcrumb-item.active {
  color: var(--text-muted);
  font-weight: 500;
}

/* ============================================
   Progress Indicators
   ============================================ */
.progress {
  height: 8px;
  background: var(--border-default);
  border-radius: 4px;
}

.progress-bar {
  background: linear-gradient(90deg, var(--primary) 0%, var(--info) 100%);
  border-radius: 4px;
  transition: width 0.4s ease;
}

/* Milestone Marker */
.milestone {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid var(--border-default);
  background: var(--bg-surface);
  display: inline-block;
  position: relative;
}

.milestone.completed {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 8px rgba(245, 158, 11, 0.3);
  animation: pulse 0.4s ease;
}

/* Spinner */
.spinner {
  border: 3px solid var(--border-default);
  border-top-color: var(--primary);
  border-radius: 50%;
  width: 24px;
  height: 24px;
  animation: spin 0.6s linear infinite;
}

.spinner-lg {
  width: 40px;
  height: 40px;
  border-width: 4px;
}

/* ============================================
   Alerts & Feedback
   ============================================ */
.alert {
  border-radius: 8px;
  padding: 16px;
  border-left-width: 4px;
}

.alert-success {
  background: var(--success-bg);
  color: var(--success-hover);
  border-color: var(--success);
  border-left-color: var(--success);
}

.alert-danger {
  background: var(--danger-bg);
  color: var(--danger-hover);
  border-color: var(--danger);
  border-left-color: var(--danger);
}

.alert-warning {
  background: var(--warning-bg);
  color: var(--warning);
  border-color: var(--warning);
  border-left-color: var(--warning);
}

.alert-info {
  background: var(--info-bg);
  color: var(--info);
  border-color: var(--info);
  border-left-color: var(--info);
}

/* ============================================
   Badges & Tags
   ============================================ */
.badge {
  padding: 6px 12px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 6px;
}

.badge-score {
  background: var(--success-bg);
  color: var(--success);
}

/* Difficulty Tags */
.tag-easy {
  background: var(--success-bg);
  color: var(--success);
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  border-radius: 4px;
}

.tag-medium {
  background: var(--warning-bg);
  color: var(--warning);
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  border-radius: 4px;
}

.tag-hard {
  background: var(--danger-bg);
  color: var(--danger);
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  border-radius: 4px;
}

/* Level Badge */
.badge-level {
  background: linear-gradient(135deg, var(--accent) 0%, #d97706 100%);
  color: white;
  padding: 8px 16px;
  border-radius: 20px;
  font-weight: 700;
  box-shadow: 0 2px 8px rgba(245, 158, 11, 0.25);
}

.badge-level.level-up {
  animation: burst 0.6s ease;
}

/* ============================================
   Dropdowns (Bootstrap override for theming)
   ============================================ */
.dropdown-menu {
  background: var(--bg-surface);
  border-color: var(--border-default);
}

.dropdown-item {
  color: var(--text-secondary);
}

.dropdown-item:hover,
.dropdown-item:focus {
  background: var(--bg-muted);
  color: var(--text-primary);
}

.dropdown-item.active {
  background: var(--primary);
  color: white;
}

.dropdown-divider {
  border-color: var(--border-default);
}

/* ============================================
   Modals
   ============================================ */
.modal-content {
  border: none;
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
}

.modal-header {
  border-bottom: 1px solid var(--border-default);
  padding: 20px 24px;
}

.modal-footer {
  border-top: 1px solid var(--border-default);
}

.modal-content {
  background: var(--bg-surface);
}

.modal-backdrop {
  background: rgba(15, 23, 42, 0.4);
  backdrop-filter: blur(2px);
}

/* ============================================
   Audio Player
   ============================================ */
.audio-play-btn {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--primary);
  border: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: white;
  transition: var(--transition-base);
  cursor: pointer;
}

.audio-play-btn:hover {
  background: var(--primary-hover);
  transform: scale(1.05);
}

.audio-play-btn:active {
  transform: scale(0.98);
}

.waveform-bar {
  width: 3px;
  background: var(--border-strong);
  border-radius: 2px;
  transition: var(--transition-fast);
  display: inline-block;
  margin: 0 2px;
}

.waveform-bar.active {
  background: var(--primary);
}

.audio-timer {
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

/* ============================================
   Stats & Data Visualization
   ============================================ */
.stat-number {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.stat-label {
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.chart-bar {
  background: linear-gradient(180deg, var(--primary) 0%, var(--info) 100%);
  border-radius: 4px 4px 0 0;
  transition: var(--transition-slow);
}

.chart-bar:hover {
  opacity: 0.85;
}

/* ============================================
   Animations
   ============================================ */
@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

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

@keyframes slideUp {
  from { transform: translateY(20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

@keyframes burst {
  0% { transform: scale(1) rotate(0deg); }
  25% { transform: scale(1.15) rotate(5deg); }
  50% { transform: scale(1.1) rotate(-5deg); }
  75% { transform: scale(1.15) rotate(5deg); }
  100% { transform: scale(1) rotate(0deg); }
}

@keyframes scaleIn {
  from { transform: scale(0.98); }
  to { transform: scale(1); }
}

/* ============================================
   Utility Classes
   ============================================ */
.text-slate-900 { color: var(--slate-900); }
.text-slate-600 { color: var(--slate-600); }
.text-slate-500 { color: var(--slate-500); }

.bg-slate-50 { background: var(--slate-50); }
.bg-slate-100 { background: var(--slate-100); }

.border-slate-200 { border-color: var(--slate-200); }

.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }

.transition-fast { transition: var(--transition-fast); }
.transition-base { transition: var(--transition-base); }

.animate-slide-up {
  animation: slideUp 0.3s ease;
}

/* Logo Styling */
.logo {
  font-size: 32px;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: -0.5px;
}

.tagline {
  font-size: 14px;
  color: var(--text-muted);
}

/* Container helpers */
.login-container {
  min-height: 100vh;
  padding: 20px;
}

.login-card {
  border: none;
  border-radius: 12px;
}

/* ============================================
   Theme Transitions
   ============================================ */
body,
.navbar,
.card,
.question-card,
.answer-option,
.form-control,
.modal-content,
.btn,
.alert,
footer {
  transition: var(--theme-transition);
}

/* ============================================
   Theme: Midnight (Dark)
   ============================================ */
[data-theme="midnight"] {
  --primary: #60a5fa;
  --primary-hover: #93bbfd;
  --success: #34d399;
  --success-hover: #6ee7b7;
  --danger: #f87171;
  --danger-hover: #fca5a5;
  --warning: #fb923c;
  --info: #38bdf8;
  --accent: #fbbf24;

  --slate-900: #f1f5f9;
  --slate-800: #e2e8f0;
  --slate-700: #cbd5e1;
  --slate-600: #94a3b8;
  --slate-500: #64748b;
  --slate-400: #475569;
  --slate-300: #334155;
  --slate-200: #1e293b;
  --slate-100: #1a2332;
  --slate-50: #0f172a;

  --bg-body: #0c1222;
  --bg-surface: #1a2332;
  --bg-surface-hover: #1e293b;
  --bg-muted: #162032;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border-default: #2a3a4e;
  --border-strong: #374a60;
  --focus-ring: rgba(96, 165, 250, 0.2);

  --success-bg: rgba(52, 211, 153, 0.15);
  --danger-bg: rgba(248, 113, 113, 0.15);
  --warning-bg: rgba(251, 146, 60, 0.15);
  --info-bg: rgba(56, 189, 248, 0.15);
  --selected-bg: rgba(96, 165, 250, 0.15);

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.5);

  /* Bootstrap overrides */
  --bs-body-bg: var(--bg-body);
  --bs-body-color: var(--text-primary);
  --bs-border-color: var(--border-default);
  color-scheme: dark;
}

/* ============================================
   Theme: Sakura (Warm Rose)
   ============================================ */
[data-theme="sakura"] {
  --primary: #be185d;
  --primary-hover: #9d174d;
  --success: #059669;
  --success-hover: #047857;
  --danger: #dc2626;
  --danger-hover: #b91c1c;
  --warning: #ea580c;
  --info: #be185d;
  --accent: #f472b6;

  --slate-900: #1c1917;
  --slate-800: #292524;
  --slate-700: #44403c;
  --slate-600: #57534e;
  --slate-500: #78716c;
  --slate-400: #a8a29e;
  --slate-300: #d6d3d1;
  --slate-200: #e7e5e4;
  --slate-100: #f5f5f4;
  --slate-50: #fafaf9;

  --bg-body: #fdf2f8;
  --bg-surface: #ffffff;
  --bg-surface-hover: #fce7f3;
  --bg-muted: #fce7f3;
  --text-primary: #1c1917;
  --text-secondary: #57534e;
  --text-muted: #78716c;
  --border-default: #f9a8d4;
  --border-strong: #f472b6;
  --focus-ring: rgba(190, 24, 93, 0.12);

  --success-bg: #d1fae5;
  --danger-bg: #fee2e2;
  --warning-bg: #fed7aa;
  --info-bg: #fce7f3;
  --selected-bg: #fce7f3;

  --shadow-sm: 0 1px 2px rgba(190, 24, 93, 0.05);
  --shadow-md: 0 4px 12px rgba(190, 24, 93, 0.08);
  --shadow-lg: 0 20px 60px rgba(190, 24, 93, 0.12);

  --bs-body-bg: var(--bg-body);
  --bs-body-color: var(--text-primary);
  --bs-border-color: var(--border-default);
}

/* ============================================
   Theme: Forest (Earthy Green)
   ============================================ */
[data-theme="forest"] {
  --primary: #15803d;
  --primary-hover: #166534;
  --success: #15803d;
  --success-hover: #166534;
  --danger: #b91c1c;
  --danger-hover: #991b1b;
  --warning: #b45309;
  --info: #0e7490;
  --accent: #a16207;

  --slate-900: #1a2e1a;
  --slate-800: #2d3b2d;
  --slate-700: #3f4f3f;
  --slate-600: #5a6b5a;
  --slate-500: #7a8a7a;
  --slate-400: #a3b0a3;
  --slate-300: #c8d1c8;
  --slate-200: #dde3dd;
  --slate-100: #eef2ee;
  --slate-50: #f5f7f5;

  --bg-body: #f7f5f0;
  --bg-surface: #fdfcf9;
  --bg-surface-hover: #f0ece4;
  --bg-muted: #eee9df;
  --text-primary: #1a2e1a;
  --text-secondary: #5a6b5a;
  --text-muted: #7a8a7a;
  --border-default: #c8d1c8;
  --border-strong: #a3b0a3;
  --focus-ring: rgba(21, 128, 61, 0.12);

  --success-bg: #dcfce7;
  --danger-bg: #fee2e2;
  --warning-bg: #fef3c7;
  --info-bg: #e0f2fe;
  --selected-bg: #dcfce7;

  --shadow-sm: 0 1px 2px rgba(26, 46, 26, 0.06);
  --shadow-md: 0 4px 12px rgba(26, 46, 26, 0.10);
  --shadow-lg: 0 20px 60px rgba(26, 46, 26, 0.15);

  --bs-body-bg: var(--bg-body);
  --bs-body-color: var(--text-primary);
  --bs-border-color: var(--border-default);
}