/* ==========================================================================
   English Hub Platform - Unified Design System
   Modern, scalable, responsive styling for interactive English learning
   ========================================================================== */

/* --- Google Fonts Import --- */
@import url('https://fonts.googleapis.com/css2?family=Cairo:wght@400;500;600;700;800;900&family=Inter:wght@400;500;600;700&display=swap');

/* --- Theme Variables & Design Tokens --- */
:root {
  /* Brand Colors */
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-glow: rgba(59, 130, 246, 0.35);
  
  --secondary: #06b6d4;
  --secondary-hover: #0891b2;
  --secondary-glow: rgba(6, 182, 212, 0.35);

  --accent: #8b5cf6;
  --accent-hover: #7c3aed;
  
  --gold: #f59e0b;
  --gold-glow: rgba(245, 158, 11, 0.35);

  --success: #10b981;
  --success-glow: rgba(16, 185, 129, 0.35);
  
  --danger: #ef4444;
  --danger-glow: rgba(239, 68, 68, 0.35);
  
  --warning: #f59e0b;
  --info: #0ea5e9;

  /* Typography */
  --font-arabic: 'Cairo', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-english: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  /* Radius & Elevation */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.18);
  --shadow-glow: 0 0 20px var(--primary-glow);

  --transition-fast: 0.18s ease;
  --transition-normal: 0.28s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.45s cubic-bezier(0.4, 0, 0.2, 1);

  /* Default to Dark Theme */
  --bg-body: #0b1120;
  --bg-surface: #111a2e;
  --bg-card: #17233f;
  --bg-card-hover: #1e2d50;
  --bg-glass: rgba(17, 26, 46, 0.78);
  
  --border-color: #223254;
  --border-subtle: #1a2844;
  --border-focus: #3b82f6;

  --text-main: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-inverse: #0b1120;

  --gradient-primary: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
  --gradient-accent: linear-gradient(135deg, #8b5cf6 0%, #ec4899 100%);
  --gradient-gold: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
  --gradient-dark: linear-gradient(180deg, #0b1120 0%, #111a2e 100%);

  /* Universal Compatibility Aliases (Dark) */
  --bg-main: var(--bg-body);
  --background-color: var(--bg-body);
  --surface-color: var(--bg-card);
  --card-bg: var(--bg-card);
  --text-primary: var(--text-main);
  --text-color: var(--text-main);
  --text-muted-color: var(--text-muted);
  --font-ar: var(--font-arabic);
  --font-en: var(--font-english);
  --primary-color: var(--primary);
  --secondary-color: var(--secondary);
  --accent-color: var(--gold);
  --success-color: var(--success);
  --accent-indigo: #6366f1;
}

/* Light Theme Overrides */
[data-theme="light"] {
  --bg-body: #f8fafc;
  --bg-surface: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-glass: rgba(255, 255, 255, 0.85);

  --border-color: #e2e8f0;
  --border-subtle: #edf2f7;
  --border-focus: #2563eb;

  --text-main: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-inverse: #ffffff;

  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
  --gradient-dark: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);

  /* Universal Compatibility Aliases (Light) */
  --bg-main: var(--bg-body);
  --background-color: var(--bg-body);
  --surface-color: var(--bg-card);
  --card-bg: var(--bg-card);
  --text-primary: var(--text-main);
  --text-color: var(--text-main);
  --text-muted-color: var(--text-muted);
  --font-ar: var(--font-arabic);
  --font-en: var(--font-english);
  --primary-color: var(--primary);
  --secondary-color: var(--secondary);
  --accent-color: var(--gold);
  --success-color: var(--success);
  --accent-indigo: #4f46e5;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  overflow-x: hidden;
  max-width: 100%;
}

body {
  font-family: var(--font-arabic);
  background-color: var(--bg-body);
  color: var(--text-main);
  direction: rtl;
  text-align: right;
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  overflow-x: hidden;
  max-width: 100%;
  width: 100%;
}

.en-font, [lang="en"], .en-text {
  font-family: var(--font-english);
  direction: ltr;
  text-align: left;
  display: inline-block;
}

/* --- Custom Scrollbar --- */
::-webkit-scrollbar {
  width: 9px;
  height: 9px;
}

::-webkit-scrollbar-track {
  background: var(--bg-body);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary);
}

/* --- Common Layout & Containers --- */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.container-narrow {
  max-width: 860px;
}

.container-wide {
  max-width: 1380px;
}

/* --- Typography Helpers --- */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 700;
  line-height: 1.3;
}

p {
  color: var(--text-secondary);
}

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

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

/* --- Modern Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.4rem;
  font-family: var(--font-arabic);
  font-size: 0.98rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-normal);
  user-select: none;
  white-space: nowrap;
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--gradient-primary);
  color: #ffffff;
  box-shadow: 0 4px 15px var(--primary-glow);
}

.btn-primary:hover {
  filter: brightness(1.1);
  box-shadow: 0 6px 20px var(--primary-glow);
  transform: translateY(-2px);
}

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

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--primary);
  transform: translateY(-2px);
}

.btn-accent {
  background: var(--gradient-accent);
  color: #ffffff;
  box-shadow: 0 4px 15px rgba(139, 92, 246, 0.35);
}

.btn-accent:hover {
  filter: brightness(1.1);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 0.45rem 0.9rem;
  font-size: 0.86rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 0.95rem 1.9rem;
  font-size: 1.12rem;
  border-radius: var(--radius-lg);
}

.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: var(--radius-md);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* --- Cards & Glassmorphism --- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.card:hover {
  border-color: var(--border-focus);
  box-shadow: var(--shadow-lg);
}

.card-interactive {
  cursor: pointer;
}

.card-interactive:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
}

.glass-panel {
  background: var(--bg-glass);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

/* --- Badges --- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.badge-primary {
  background: rgba(59, 130, 246, 0.15);
  color: var(--primary);
  border-color: rgba(59, 130, 246, 0.3);
}

.badge-success {
  background: rgba(16, 185, 129, 0.15);
  color: var(--success);
  border-color: rgba(16, 185, 129, 0.3);
}

.badge-gold {
  background: rgba(245, 158, 11, 0.15);
  color: var(--gold);
  border-color: rgba(245, 158, 11, 0.3);
}

.badge-accent {
  background: rgba(139, 92, 246, 0.15);
  color: var(--accent);
  border-color: rgba(139, 92, 246, 0.3);
}

/* --- Form Controls --- */
.form-control, .input-field, select.form-select {
  width: 100%;
  padding: 0.75rem 1rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-family: var(--font-arabic);
  font-size: 0.95rem;
  transition: all var(--transition-fast);
  outline: none;
}

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

/* --- Progress Bar Component --- */
.progress-track {
  width: 100%;
  height: 10px;
  background-color: var(--border-subtle);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-normal);
}

/* --- Speech / Audio Action Button --- */
.btn-speech {
  background: rgba(59, 130, 246, 0.12);
  color: var(--primary);
  border: 1px solid rgba(59, 130, 246, 0.25);
  border-radius: var(--radius-full);
  width: 38px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-speech:hover {
  background: var(--primary);
  color: #ffffff;
  transform: scale(1.08);
}

.btn-speech.speaking {
  animation: pulse-glow 1.2s infinite alternate;
  background: var(--primary);
  color: #ffffff;
}

@keyframes pulse-glow {
  0% { box-shadow: 0 0 0 0 var(--primary-glow); transform: scale(1); }
  100% { box-shadow: 0 0 16px 4px var(--primary-glow); transform: scale(1.06); }
}

/* --- Animations --- */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.4s ease forwards;
}

/* --- Tactical & Filter Pill Buttons --- */
.pill-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.5rem 1.2rem;
  border-radius: var(--radius-full);
  font-size: 0.92rem;
  font-weight: 700;
  font-family: var(--font-arabic);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: var(--shadow-sm);
  user-select: none;
  touch-action: manipulation;
}

.pill-btn:hover {
  border-color: var(--primary);
  color: var(--text-main);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.pill-btn.active {
  background: var(--gradient-primary);
  border-color: var(--primary);
  color: #ffffff;
  box-shadow: 0 4px 16px var(--primary-glow);
}

/* --- Mobile Touch & Accessibility --- */
* {
  -webkit-tap-highlight-color: transparent;
}

button, a, input, select, .btn, .pill-btn {
  touch-action: manipulation;
}

/* --- Responsive Helpers --- */
@media (max-width: 768px) {
  html {
    font-size: 15px;
  }
  .container {
    padding: 0 1rem;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 14.5px;
  }
  .container {
    padding: 0 0.85rem;
  }
  .btn {
    min-height: 44px;
  }
}

/* --- Safe Area Inset Support (Notch Devices) --- */
@supports (padding: max(0px)) {
  body {
    padding-left: max(0px, env(safe-area-inset-left));
    padding-right: max(0px, env(safe-area-inset-right));
    padding-bottom: max(0px, env(safe-area-inset-bottom));
  }
}