/* ============================================================\n   English Learning Platform - Main Stylesheet
   Theme: Green (Nature / Growth)
   Primary: #0d7c3f  |  Secondary: #1a9e5a  |  Accent: #34d07c  |  Light: #e8f5e9
   Fonts:  Poppins (headings)  |  Roboto (body)
   ============================================================ */

/* ----------------------------------------------------------
   1. CSS Custom Properties (Light Mode Defaults)
   ---------------------------------------------------------- */
:root {
  /* Brand Colors */
  --color-primary: #0d7c3f;
  --color-secondary: #1a9e5a;
  --color-accent: #34d07c;
  --color-light: #e8f5e9;

  /* Semantic Colors */
  --color-success: #28a745;
  --color-danger: #dc3545;
  --color-warning: #fd7e14;
  --color-info: #17a2b8;

  /* Neutrals */
  --color-white: #ffffff;
  --color-gray-50: #f8f9fa;
  --color-gray-100: #f1f3f5;
  --color-gray-200: #e9ecef;
  --color-gray-300: #dee2e6;
  --color-gray-400: #ced4da;
  --color-gray-500: #adb5bd;
  --color-gray-600: #868e96;
  --color-gray-700: #495057;
  --color-gray-800: #343a40;
  --color-gray-900: #212529;

  /* Typography */
  --font-heading: 'Poppins', sans-serif;
  --font-body: 'Roboto', sans-serif;

  /* Spacing Scale */
  --space-xs: 0.25rem;   /* 4px */
  --space-sm: 0.5rem;    /* 8px */
  --space-md: 1rem;      /* 16px */
  --space-lg: 1.5rem;    /* 24px */
  --space-xl: 2rem;      /* 32px */
  --space-2xl: 3rem;     /* 48px */
  --space-3xl: 4rem;     /* 64px */

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 12px 40px rgba(0, 0, 0, 0.16);

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;

  /* Layout */
  --navbar-height: 70px;
  --sidebar-width: 260px;
  --max-width: 1200px;

  /* Surfaces */
  --bg-body: #f5f7fa;
  --bg-card: #ffffff;
  --bg-navbar: rgba(255, 255, 255, 0.95);
  --bg-input: #ffffff;
  --text-primary: #212529;
  --text-secondary: #495057;
  --text-muted: #868e96;
  --border-color: #dee2e6;
}

/* ----------------------------------------------------------
   2. Dark Mode Variables
   ---------------------------------------------------------- */
.dark-mode {
  --color-light: #1a2e1f;

  --bg-body: #121212;
  --bg-card: #1e1e1e;
  --bg-navbar: rgba(30, 30, 30, 0.95);
  --bg-input: #2a2a2a;
  --text-primary: #e9ecef;
  --text-secondary: #adb5bd;
  --text-muted: #868e96;
  --border-color: #3a3a3a;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 12px 40px rgba(0, 0, 0, 0.6);

  --color-gray-50: #1e1e1e;
  --color-gray-100: #2a2a2a;
  --color-gray-200: #3a3a3a;
  --color-gray-300: #4a4a4a;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-slow), color var(--transition-slow);
}

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

a:hover {
  color: var(--color-secondary);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Transition all interactive elements */
a, button, input, select, textarea, [role="button"], .card, .badge {
  transition: all var(--transition-base);
}

/* ----------------------------------------------------------
   4. Typography
   ---------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.3;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.1rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
}

/* Section title with green underline */
.section-title {
  position: relative;
  display: inline-block;
  margin-bottom: var(--space-xl);
  font-weight: 700;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-full);
}

.section-title.text-center::after {
  left: 50%;
  transform: translateX(-50%);
}

/* ----------------------------------------------------------
   5. Navbar
   ---------------------------------------------------------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--navbar-height);
  background: var(--bg-navbar);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1050;
  display: flex;
  align-items: center;
  padding: 0 var(--space-xl);
  transition: box-shadow var(--transition-base), background-color var(--transition-slow);
}

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

.navbar .navbar-brand {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.navbar .navbar-brand:hover {
  color: var(--color-secondary);
}

.navbar .navbar-brand i {
  font-size: 1.6rem;
}

.navbar-nav {
  display: flex;
  list-style: none;
  align-items: center;
  gap: var(--space-xs);
  margin: 0;
  padding: 0;
}

.navbar-nav .nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  color: var(--text-secondary);
  font-weight: 500;
  border-radius: var(--radius-sm);
  position: relative;
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
  color: var(--color-primary);
  background-color: var(--color-light);
}

.navbar-nav .nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: var(--space-md);
  right: var(--space-md);
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-full);
}

.navbar .navbar-toggler {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-primary);
  cursor: pointer;
  padding: var(--space-sm);
}

/* Dark mode toggle button in navbar */
.dark-mode-toggle {
  background: none;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-full);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 1.1rem;
  transition: all var(--transition-base);
}

.dark-mode-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background-color: var(--color-light);
}

/* ----------------------------------------------------------
   6. Buttons
   ---------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0.625rem 1.5rem;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  text-decoration: none;
  line-height: 1.4;
  position: relative;
  overflow: hidden;
  transition: all var(--transition-base);
}

.btn:active {
  transform: scale(0.97);
}

/* Green gradient button */
.btn-green {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: var(--color-white);
  box-shadow: 0 4px 15px rgba(13, 124, 63, 0.3);
}

.btn-green:hover {
  background: linear-gradient(135deg, #0a6332, var(--color-secondary));
  color: var(--color-white);
  box-shadow: 0 6px 20px rgba(13, 124, 63, 0.45);
  transform: translateY(-2px);
}

.btn-green:active {
  transform: translateY(0) scale(0.97);
}

/* Button outline variant */
.btn-outline-green {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-outline-green:hover {
  background: var(--color-primary);
  color: var(--color-white);
  transform: translateY(-2px);
}

/* Button sizes */
.btn-sm {
  padding: 0.375rem 1rem;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 0.875rem 2rem;
  font-size: 1.1rem;
}

/* Ripple effect keyframes */
@keyframes ripple {
  0% {
    transform: scale(0);
    opacity: 0.5;
  }
  100% {
    transform: scale(4);
    opacity: 0;
  }
}

.btn .ripple-effect {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  pointer-events: none;
  animation: ripple 600ms ease-out forwards;
}

/* ----------------------------------------------------------
   7. Cards
   ---------------------------------------------------------- */
.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
  overflow: hidden;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card-header {
  padding: var(--space-lg);
  border-bottom: 1px solid var(--border-color);
  background-color: var(--color-gray-50);
}

.dark-mode .card-header {
  background-color: var(--color-gray-100);
}

.card-body {
  padding: var(--space-lg);
}

.card-footer {
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--border-color);
  background-color: var(--color-gray-50);
}

.dark-mode .card-footer {
  background-color: var(--color-gray-100);
}

.card-title {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.card-img-top {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

/* ----------------------------------------------------------
   8. Forms
   ---------------------------------------------------------- */
.form-group {
  position: relative;
  margin-bottom: var(--space-lg);
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--text-primary);
  background: var(--bg-input);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  outline: none;
}

.form-control::placeholder {
  color: var(--text-muted);
}

.form-control:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(13, 124, 63, 0.15);
}

.form-control.is-valid {
  border-color: var(--color-success);
}

.form-control.is-valid:focus {
  box-shadow: 0 0 0 3px rgba(40, 167, 69, 0.15);
}

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

.form-control.is-invalid:focus {
  box-shadow: 0 0 0 3px rgba(220, 53, 69, 0.15);
}

/* Floating labels style */
.form-floating-label {
  position: relative;
}

.form-floating-label .form-control {
  padding-top: 1.25rem;
  padding-bottom: 0.25rem;
}

.form-floating-label label {
  position: absolute;
  top: 50%;
  left: 1rem;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 1rem;
  pointer-events: none;
  transition: all var(--transition-fast);
  background: var(--bg-input);
  padding: 0 0.25rem;
}

.form-floating-label .form-control:focus ~ label,
.form-floating-label .form-control:not(:placeholder-shown) ~ label {
  top: 0;
  font-size: 0.75rem;
  color: var(--color-primary);
  font-weight: 600;
}

/* ----------------------------------------------------------
   9. Progress Bars
   ---------------------------------------------------------- */
.progress {
  height: 10px;
  background: var(--color-gray-200);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-full);
  transition: width 0.8s cubic-bezier(0.25, 0.8, 0.25, 1);
  position: relative;
}

/* Animated fill effect */
.progress-bar.animated::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    90deg,
    transparent 0%,
    rgba(255, 255, 255, 0.3) 50%,
    transparent 100%
  );
  animation: progress-shimmer 2s ease-in-out infinite;
}

@keyframes progress-shimmer {
  0%   { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

/* ----------------------------------------------------------
   10. Badges (by level)
   ---------------------------------------------------------- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25em 0.6em;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  line-height: 1.4;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.badge-beginner {
  background-color: #e3f2fd;
  color: #1565c0;
}

.badge-intermediate {
  background-color: #fff3e0;
  color: #e65100;
}

.badge-advanced {
  background-color: var(--color-light);
  color: var(--color-primary);
}

.dark-mode .badge-beginner {
  background-color: #0d2b4d;
  color: #64b5f6;
}

.dark-mode .badge-intermediate {
  background-color: #3e2723;
  color: #ffb74d;
}

.dark-mode .badge-advanced {
  background-color: #1a2e1f;
  color: var(--color-accent);
}

/* ----------------------------------------------------------
   11. Hero Section
   ---------------------------------------------------------- */
.hero-section {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--navbar-height) + var(--space-2xl)) var(--space-xl) var(--space-2xl);
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(13, 124, 63, 0.9), rgba(26, 158, 90, 0.85), rgba(52, 208, 124, 0.8));
  z-index: 0;
}

.hero-section .hero-bg-image {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  z-index: -1;
}

.hero-section .hero-content {
  position: relative;
  z-index: 1;
  max-width: 700px;
}

.hero-section h1 {
  font-size: 3rem;
  font-weight: 800;
  color: var(--color-white);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
  margin-bottom: var(--space-lg);
}

.hero-section p {
  font-size: 1.2rem;
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.15);
  margin-bottom: var(--space-xl);
}

.hero-section .btn-green {
  padding: 0.875rem 2.5rem;
  font-size: 1.1rem;
  border-radius: var(--radius-xl);
}

/* ----------------------------------------------------------
   12. Stat Cards
   ---------------------------------------------------------- */
.stat-card {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  color: var(--color-white);
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  box-shadow: 0 4px 20px rgba(13, 124, 63, 0.3);
 transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(13, 124, 63, 0.4);
}

.stat-card .stat-icon {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}

.stat-card .stat-number {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.2;
}

.stat-card .stat-label {
  font-size: 0.9rem;
  opacity: 0.9;
  margin-bottom: 0;
  color: var(--color-white);
}

/* ----------------------------------------------------------
   13. Chat
   ---------------------------------------------------------- */
.chat-container {
  display: flex;
  flex-direction: column;
  height: 500px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

/* Custom scrollbar for chat */
.chat-messages::-webkit-scrollbar {
  width: 6px;
}

.chat-messages::-webkit-scrollbar-track {
  background: transparent;
}

.chat-messages::-webkit-scrollbar-thumb {
  background: var(--color-gray-300);
  border-radius: var(--radius-full);
}

/* Message bubbles */
.message-bubble {
  max-width: 70%;
  padding: var(--space-sm) var(--space-md);
  border-radius: 18px;
  font-size: 0.95rem;
  line-height: 1.5;
  word-wrap: break-word;
  animation: messageSlideIn 0.3s ease-out;
}

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

/* Sent message (right-aligned, green) */
.message-sent {
  align-self: flex-end;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: var(--color-white);
  border-bottom-right-radius: 4px;
}

/* Received message (left-aligned, gray) */
.message-received {
  align-self: flex-start;
  background: var(--color-gray-200);
  color: var(--text-primary);
  border-bottom-left-radius: 4px;
}

.dark-mode .message-received {
  background: var(--color-gray-100);
  color: var(--text-primary);
}

.message-time {
  font-size: 0.7rem;
  opacity: 0.7;
  margin-top: var(--space-xs);
}

.message-sent .message-time {
  text-align: right;
  color: rgba(255, 255, 255, 0.7);
}

/* Typing indicator */
.typing-indicator {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: var(--space-sm) var(--space-md);
  background: var(--color-gray-200);
  border-radius: 18px;
  border-bottom-left-radius: 4px;
  align-self: flex-start;
}

.dark-mode .typing-indicator {
  background: var(--color-gray-100);
}

.typing-indicator span {
  width: 8px;
  height: 8px;
  background: var(--color-gray-500);
  border-radius: 50%;
  animation: typingBounce 1.4s infinite;
}

.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }

@keyframes typingBounce {
  0%, 60%, 100% {
    transform: translateY(0);
    opacity: 0.4;
  }
  30% {
    transform: translateY(-6px);
    opacity: 1;
  }
}

/* Chat input area */
.chat-input-area {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  border-top: 1px solid var(--border-color);
  background: var(--bg-card);
}

.chat-input-area .form-control {
  border-radius: var(--radius-xl);
  padding: 0.625rem 1.25rem;
}

.chat-input-area .btn {
  border-radius: 50%;
  width: 44px;
  height: 44px;
  padding: 0;
  flex-shrink: 0;
}

/* ----------------------------------------------------------
   14. Study Timer
   ---------------------------------------------------------- */
.timer-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-lg);
}

.timer-circle {
  position: relative;
  width: 220px;
  height: 220px;
}

.timer-circle svg {
  transform: rotate(-90deg);
  width: 100%;
  height: 100%;
}

.timer-circle .timer-track {
  fill: none;
  stroke: var(--color-gray-200);
  stroke-width: 8;
}

.dark-mode .timer-circle .timer-track {
  stroke: var(--color-gray-300);
}

.timer-circle .timer-progress {
  fill: none;
  stroke: url(#timerGradient);
  stroke-width: 8;
  stroke-linecap: round;
  transition: stroke-dashoffset 1s linear;
}

.timer-display {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}

.timer-display .timer-time {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 2px;
}

.timer-display .timer-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.timer-controls {
  display: flex;
  gap: var(--space-md);
}

/* ----------------------------------------------------------
   15. Achievement Badges
   ---------------------------------------------------------- */
.achievement-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  text-align: center;
}

.achievement-badge .badge-icon {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: var(--color-white);
  box-shadow: 0 4px 15px rgba(13, 124, 63, 0.3);
  transition: transform var(--transition-base);
}

.achievement-badge:hover .badge-icon {
  transform: scale(1.1) rotate(5deg);
}

/* Hexagon shape variant */
.achievement-badge.hexagon .badge-icon {
  clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
  border-radius: 0;
  width: 80px;
  height: 92px;
}

/* Locked (not yet earned) badge */
.achievement-badge.locked .badge-icon {
  background: var(--color-gray-300);
  opacity: 0.5;
  box-shadow: none;
  filter: grayscale(100%);
}

.dark-mode .achievement-badge.locked .badge-icon {
  background: var(--color-gray-300);
}

.achievement-badge.locked .badge-name {
  color: var(--text-muted);
}

.achievement-badge .badge-name {
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
}

.achievement-badge .badge-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* ----------------------------------------------------------
   16. Bookmark Star Animation
   ---------------------------------------------------------- */
.bookmark-star {
  cursor: pointer;
  font-size: 1.25rem;
  color: var(--color-gray-400);
  transition: color var(--transition-fast), transform var(--transition-fast);
}

.bookmark-star:hover {
  color: #ffc107;
  transform: scale(1.15);
}

.bookmark-star.active {
  color: #ffc107;
}

/* Star pop animation */
@keyframes starPop {
  0%   { transform: scale(1); }
  30%  { transform: scale(1.4) rotate(15deg); }
  50%  { transform: scale(0.9) rotate(-5deg); }
  70%  { transform: scale(1.1) rotate(3deg); }
  100% { transform: scale(1) rotate(0deg); }
}

.bookmark-star.pop {
  animation: starPop 0.5s ease;
}

/* ----------------------------------------------------------
   17. Ad Banner
   ---------------------------------------------------------- */
.ad-banner {
  background: linear-gradient(135deg, var(--color-light), #c8e6c9);
  border: 2px dashed var(--color-secondary);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  text-align: center;
  color: var(--color-primary);
  font-size: 0.85rem;
  position: relative;
  overflow: hidden;
}

.dark-mode .ad-banner {
  background: linear-gradient(135deg, var(--color-light), #1a2e1f);
  border-color: var(--color-primary);
  color: var(--color-accent);
}

.ad-banner .ad-label {
  position: absolute;
  top: var(--space-xs);
  right: var(--space-xs);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  opacity: 0.6;
}

/* ----------------------------------------------------------
   18. Certificate Card
   ---------------------------------------------------------- */
.certificate-card {
  background: var(--bg-card);
  border: 3px solid var(--color-primary);
  border-radius: var(--radius-lg);
  padding: var(--space-2xl);
  text-align: center;
  position: relative;
  box-shadow: var(--shadow-md);
}

.certificate-card::before {
  content: '';
  position: absolute;
  top: 10px;
  left: 10px;
  right: 10px;
  bottom: 10px;
  border: 2px solid var(--color-accent);
  border-radius: var(--radius-md);
  pointer-events: none;
}

.certificate-card .certificate-seal {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  margin: 0 auto var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: var(--color-white);
  box-shadow: 0 4px 15px rgba(13, 124, 63, 0.3);
}

.certificate-card h3 {
  font-size: 1.75rem;
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
}

.certificate-card .certificate-recipient {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-lg);
}

.certificate-card .certificate-date {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ----------------------------------------------------------
   19. Dictionary Search Results
   ---------------------------------------------------------- */
.dictionary-results {
  max-height: 400px;
  overflow-y: auto;
}

.dict-result-item {
  padding: var(--space-md);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-fast);
  cursor: pointer;
}

.dict-result-item:last-child {
  border-bottom: none;
}

.dict-result-item:hover {
  background-color: var(--color-light);
}

.dict-result-item .dict-word {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
}

.dict-result-item .dict-phonetic {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
}

.dict-result-item .dict-definition {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-xs);
}

.dict-result-item .dict-part-of-speech {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  font-style: italic;
  color: var(--color-secondary);
  margin-right: var(--space-sm);
}

/* Autocomplete dropdown */
.autocomplete-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-height: 250px;
  overflow-y: auto;
  z-index: 1000;
  display: none;
}

.autocomplete-dropdown.show {
  display: block;
}

.autocomplete-item {
  padding: var(--space-sm) var(--space-md);
  cursor: pointer;
  font-size: 0.95rem;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-fast);
}

.autocomplete-item:last-child {
  border-bottom: none;
}

.autocomplete-item:hover,
.autocomplete-item.active {
  background-color: var(--color-light);
  color: var(--color-primary);
}

/* ----------------------------------------------------------
   20. 404 Page
   ---------------------------------------------------------- */
.error-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-xl);
  background: var(--bg-body);
}

.error-page .error-code {
  font-family: var(--font-heading);
  font-size: 8rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: errorPulse 3s ease-in-out infinite;
  line-height: 1;
  margin-bottom: var(--space-md);
}

@keyframes errorPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50%      { transform: scale(1.05); opacity: 0.8; }
}

.error-page h2 {
  font-size: 1.5rem;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.error-page p {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin-bottom: var(--space-xl);
}

/* Floating animation for 404 illustrations */
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-15px); }
}

.error-page .floating {
  animation: float 3s ease-in-out infinite;
}

/* ----------------------------------------------------------
   21. Footer
   ---------------------------------------------------------- */
.footer {
  background: linear-gradient(135deg, var(--color-primary), #0a5c2e);
  color: var(--color-white);
  padding: var(--space-3xl) var(--space-xl) var(--space-xl);
 margin-top: auto;
}

.footer h5 {
  color: var(--color-white);
  font-size: 1.1rem;
  margin-bottom: var(--space-lg);
  position: relative;
  padding-bottom: var(--space-sm);
}

.footer h5::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--color-accent);
  border-radius: var(--radius-full);
}

.footer p,
.footer a {
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.95rem;
  margin-bottom: var(--space-sm);
}

.footer a:hover {
  color: var(--color-white);
}

.footer-links {
  list-style: none;
  padding: 0;
}

.footer-links li {
  margin-bottom: var(--space-sm);
}

.footer-links a {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: var(--space-lg);
  margin-top: var(--space-xl);
  text-align: center;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.6);
}

/* ----------------------------------------------------------
   22. Quiz Styles
   ---------------------------------------------------------- */
.quiz-container {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: var(--space-xl);
  align-items: start;
}

.quiz-question-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

.quiz-question-number {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--space-sm);
}

.quiz-question-text {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-xl);
  line-height: 1.5;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--bg-card);
}

.quiz-option:hover {
  border-color: var(--color-primary);
  background: var(--color-light);
}

.quiz-option.selected {
  border-color: var(--color-primary);
  background: var(--color-light);
}

.quiz-option.correct {
  border-color: var(--color-success);
  background: #d4edda;
}

.dark-mode .quiz-option.correct {
  background: #1a3a2a;
}

.quiz-option.incorrect {
  border-color: var(--color-danger);
  background: #f8d7da;
}

.dark-mode .quiz-option.incorrect {
  background: #3a1a1a;
}

.quiz-option .option-letter {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-gray-200);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-secondary);
  flex-shrink: 0;
  transition: all var(--transition-fast);
}

.quiz-option.selected .option-letter {
  background: var(--color-primary);
  color: var(--color-white);
}

.quiz-option.correct .option-letter {
  background: var(--color-success);
  color: var(--color-white);
}

.quiz-option.incorrect .option-letter {
  background: var(--color-danger);
  color: var(--color-white);
}

/* Quiz navigation sidebar */
.quiz-nav {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
  position: sticky;
  top: calc(var(--navbar-height) + var(--space-lg));
}

.quiz-nav-title {
  font-family: var(--font-heading);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--space-md);
}

.quiz-nav-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-sm);
}

.quiz-nav-item {
  width: 100%;
  aspect-ratio: 1;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--bg-card);
}

.quiz-nav-item:hover {
  border-color: var(--color-primary);
}

.quiz-nav-item.current {
  border-color: var(--color-primary);
  background: var(--color-light);
  color: var(--color-primary);
}

.quiz-nav-item.answered {
  border-color: var(--color-secondary);
  background: var(--color-light);
  color: var(--color-primary);
}

/* Quiz progress tracker */
.quiz-progress {
  margin-top: var(--space-lg);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--border-color);
}

.quiz-progress-text {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
}

/* Quiz timer in header */
.quiz-timer {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.quiz-timer.warning {
  color: var(--color-danger);
  animation: timerPulse 1s ease-in-out infinite;
}

@keyframes timerPulse {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.5; }
}

/* Score display */
.score-display {
  text-align: center;
  padding: var(--space-2xl);
}

.score-circle {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-xl);
  color: var(--color-white);
  box-shadow: 0 8px 30px rgba(13, 124, 63, 0.3);
 animation: scoreAppear 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes scoreAppear {
  from {
    transform: scale(0);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

.score-circle .score-number {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1;
}

.score-circle .score-label {
  font-size: 0.8rem;
  opacity: 0.9;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* ----------------------------------------------------------
   23. Utility Classes
   ---------------------------------------------------------- */
.text-green   { color: var(--color-primary) !important; }
.text-accent   { color: var(--color-accent) !important; }
.text-muted    { color: var(--text-muted) !important; }
.bg-light      { background-color: var(--color-light) !important; }
.bg-green      { background-color: var(--color-primary) !important; }

.mt-1 { margin-top: var(--space-sm); }
.mt-2 { margin-top: var(--space-md); }
.mt-3 { margin-top: var(--space-lg); }
.mt-4 { margin-top: var(--space-xl); }

.mb-1 { margin-bottom: var(--space-sm); }
.mb-2 { margin-bottom: var(--space-md); }
.mb-3 { margin-bottom: var(--space-lg); }
.mb-4 { margin-bottom: var(--space-xl); }

.p-1 { padding: var(--space-sm); }
.p-2 { padding: var(--space-md); }
.p-3 { padding: var(--space-lg); }
.p-4 { padding: var(--space-xl); }

.d-none   { display: none !important; }
.d-flex   { display: flex !important; }
.d-grid   { display: grid !important; }
.gap-1    { gap: var(--space-sm); }
.gap-2    { gap: var(--space-md); }
.gap-3    { gap: var(--space-lg); }

.text-center { text-align: center; }
.text-right  { text-align: right; }

.w-100 { width: 100%; }

.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: var(--radius-full); }

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

/* ----------------------------------------------------------
   24. Responsive Breakpoints
   ---------------------------------------------------------- */

/* Small devices (phones, 576px and up) */
@media (max-width: 575.98px) {
  :root {
    --navbar-height: 60px;
  }

  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }

  .navbar {
    padding: 0 var(--space-md);
  }

  .navbar .navbar-collapse {
    display: none;
    position: absolute;
    top: var(--navbar-height);
    left: 0;
    right: 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    padding: var(--space-md);
  }

  .navbar .navbar-collapse.show {
    display: block;
  }

  .navbar-nav {
    flex-direction: column;
    width: 100%;
  }

  .navbar .navbar-toggler {
    display: flex;
  }

  .hero-section {
    min-height: 70vh;
    padding: calc(var(--navbar-height) + var(--space-xl)) var(--space-md) var(--space-xl);
  }

  .hero-section h1 {
    font-size: 2rem;
  }

  .stat-card {
    flex-direction: column;
    text-align: center;
  }

  .quiz-container {
    grid-template-columns: 1fr;
  }

  .quiz-nav {
    position: static;
  }

  .timer-circle {
    width: 180px;
    height: 180px;
  }

  .timer-display .timer-time {
    font-size: 2rem;
  }

  .message-bubble {
    max-width: 85%;
  }

  .certificate-card {
    padding: var(--space-lg);
  }
}

/* Medium devices (tablets, 768px and up) */
@media (min-width: 576px) and (max-width: 767.98px) {
  .navbar .navbar-collapse {
    display: none;
    position: absolute;
    top: var(--navbar-height);
    left: 0;
    right: 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    padding: var(--space-md);
  }

  .navbar .navbar-collapse.show {
    display: block;
  }

  .navbar-nav {
    flex-direction: column;
    width: 100%;
  }

  .navbar .navbar-toggler {
    display: flex;
  }

  .quiz-container {
    grid-template-columns: 1fr 220px;
  }
}

/* Large devices (desktops, 992px and up) */
@media (min-width: 768px) and (max-width: 991.98px) {
  .hero-section h1 {
    font-size: 2.5rem;
  }
}

/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 992px) {
  .hero-section h1 {
    font-size: 3.25rem;
  }
}

@media (min-width: 1200px) {
  .hero-section h1 {
    font-size: 3.5rem;
  }
}

/* ----------------------------------------------------------
   25. AOS (Animate On Scroll) Custom Overrides
   ---------------------------------------------------------- */
[data-aos] {
  transition-timing-function: cubic-bezier(0.25, 0.8, 0.25, 1) !important;
}

/* Fade up custom variation */
[data-aos="fade-up-green"] {
  background: linear-gradient(to top, rgba(13, 124, 63, 0.05), transparent);
}

/* Stagger children delay for lists / grids */
.stagger-children > *:nth-child(1)  { transition-delay: 0ms; }
.stagger-children > *:nth-child(2)  { transition-delay: 80ms; }
.stagger-children > *:nth-child(3)  { transition-delay: 160ms; }
.stagger-children > *:nth-child(4)  { transition-delay: 240ms; }
.stagger-children > *:nth-child(5)  { transition-delay: 320ms; }
.stagger-children > *:nth-child(6)  { transition-delay: 400ms; }
.stagger-children > *:nth-child(7)  { transition-delay: 480ms; }
.stagger-children > *:nth-child(8)  { transition-delay: 560ms; }

/* ----------------------------------------------------------
   26. Scrollbar Styling (Dark Mode Friendly)
   ---------------------------------------------------------- */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--color-gray-400);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-gray-500);
}

/* ----------------------------------------------------------
   27. Selection Color
   ---------------------------------------------------------- */
::selection {
  background: var(--color-accent);
  color: var(--color-white);
}

/* ----------------------------------------------------------
   28. Page Content Wrapper (accounts for fixed navbar)
   ---------------------------------------------------------- */
.page-content {
  padding-top: var(--navbar-height);
  min-height: calc(100vh - 60px);
  display: flex;
  flex-direction: column;
}

/* ----------------------------------------------------------
   29. SweetAlert2 Theme Overrides
   ---------------------------------------------------------- */
.swal2-popup.swal2-modal {
  font-family: var(--font-body);
  border-radius: var(--radius-lg);
}

.swal2-title {
  font-family: var(--font-heading);
}

.swal2-confirm.swal2-styled {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent)) !important;
  border-radius: var(--radius-md) !important;
  font-family: var(--font-heading) !important;
}

/* ----------------------------------------------------------
   30. Loading Spinner
   ---------------------------------------------------------- */
.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--color-gray-200);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.spinner-sm {
  width: 20px;
  height: 20px;
  border-width: 2px;
}