:root {
  --primary-color: #2563eb;
  --primary-light: #3b82f6;
  --primary-dark: #1d4ed8;
  --secondary-color: #8b5cf6;
  --accent-color: #f59e0b;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --text-light: #9ca3af;
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --bg-tertiary: #f3f4f6;
  --border-color: #e5e7eb;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --border-radius-sm: 0.25rem;
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --max-width: 1200px;
  --header-height: 4rem;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-sm);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
}

.btn-primary {
  background-color: var(--primary-color);
  color: white;
}

.btn-primary:hover {
  background-color: var(--primary-dark);
}

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

.btn-secondary:hover {
  background-color: #7c3aed;
}

.btn-outline {
  background-color: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
}

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

.btn-accent {
  background-color: var(--accent-color);
  color: white;
}

.btn-accent:hover {
  background-color: #d97706;
}

.btn-sm {
  padding: 0.25rem 0.75rem;
  font-size: 0.875rem;
}

.btn-lg {
  padding: 0.75rem 1.5rem;
  font-size: 1.125rem;
}

.btn-block {
  width: 100%;
  display: flex;
}

.card {
  background: var(--bg-primary);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}

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

.card-header {
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
}

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

.card-footer {
  padding: var(--spacing-md) var(--spacing-lg);
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-tertiary);
}

.grid {
  display: grid;
  gap: var(--spacing-lg);
}

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

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

.grid-cols-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-cols-4 {
  grid-template-columns: repeat(4, 1fr);
}

.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-between {
  justify-content: space-between;
}

.justify-center {
  justify-content: center;
}

.gap-sm {
  gap: var(--spacing-sm);
}

.gap-md {
  gap: var(--spacing-md);
}

.gap-lg {
  gap: var(--spacing-lg);
}

.section {
  padding: var(--spacing-2xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
  color: var(--text-primary);
}

.form-control {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  font-size: 1rem;
  transition: border-color 0.2s ease;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-text {
  margin-top: var(--spacing-sm);
  font-size: 0.875rem;
  color: var(--text-light);
}

.alert {
  padding: var(--spacing-md);
  border-radius: var(--border-radius-sm);
  margin-bottom: var(--spacing-lg);
}

.alert-success {
  background-color: #d1fae5;
  border-left: 4px solid var(--success-color);
  color: #065f46;
}

.alert-error {
  background-color: #fee2e2;
  border-left: 4px solid var(--error-color);
  color: #991b1b;
}

.alert-warning {
  background-color: #fef3c7;
  border-left: 4px solid var(--warning-color);
  color: #92400e;
}

.table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-primary);
  border-radius: var(--border-radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.table th,
.table td {
  padding: var(--spacing-md);
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.table th {
  background-color: var(--bg-tertiary);
  font-weight: 600;
  color: var(--text-primary);
}

.table tr:last-child td {
  border-bottom: none;
}

.table tr:hover td {
  background-color: var(--bg-secondary);
}

.badge {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  border-radius: var(--border-radius-sm);
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
}

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

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

.badge-warning {
  background-color: var(--warning-color);
  color: white;
}

.badge-error {
  background-color: var(--error-color);
  color: white;
}

.avatar {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  object-fit: cover;
}

.avatar-sm {
  width: 1.5rem;
  height: 1.5rem;
}

.avatar-lg {
  width: 4rem;
  height: 4rem;
}

.avatar-xl {
  width: 6rem;
  height: 6rem;
}

.header {
  background-color: var(--bg-primary);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) 0;
}

.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  gap: var(--spacing-lg);
}

.nav-item a {
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 500;
  transition: color 0.2s ease;
}

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

.nav-item a.active {
  color: var(--primary-color);
  position: relative;
}

.nav-item a.active::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--primary-color);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-primary);
}

.footer {
  background-color: var(--bg-secondary);
  padding: var(--spacing-xl) 0;
  margin-top: var(--spacing-2xl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-lg);
}

.footer-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

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

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

.footer-links a {
  text-decoration: none;
  color: var(--text-secondary);
  transition: color 0.2s ease;
}

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

.copyright {
  text-align: center;
  padding-top: var(--spacing-lg);
  margin-top: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
  color: var(--text-light);
  font-size: 0.875rem;
}

.hero {
  background: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
  color: white;
  padding: 4rem 0;
  text-align: center;
}

.hero-content {
  max-width: 800px;
  margin: 0 auto;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
}

.hero-subtitle {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-lg);
  opacity: 0.9;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.program-card {
  text-align: center;
  padding: var(--spacing-lg);
}

.program-icon {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: var(--spacing-md);
}

.program-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.teacher-card {
  text-align: center;
}

.teacher-avatar {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: var(--border-radius-md) var(--border-radius-md) 0 0;
}

.teacher-info {
  padding: var(--spacing-lg);
}

.teacher-name {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.teacher-position {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-md);
}

.teacher-bio {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.gallery-item {
  border-radius: var(--border-radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease;
}

.gallery-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

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

.course-card {
  height: 100%;
  display: flex;
  flex-direction: column;
}

.course-header {
  position: relative;
  overflow: hidden;
}

.course-image {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.course-badge {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
}

.course-content {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.course-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.course-excerpt {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-md);
  flex: 1;
}

.course-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--border-color);
}

.schedule-table {
  width: 100%;
  border-collapse: collapse;
}

.schedule-table th,
.schedule-table td {
  padding: var(--spacing-md);
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.schedule-table th {
  background-color: var(--bg-tertiary);
  font-weight: 600;
}

.schedule-table tr:last-child td {
  border-bottom: none;
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

.post-card {
  height: 100%;
  display: flex;
  flex-direction: column;
}

.post-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: var(--border-radius-md) var(--border-radius-md) 0 0;
}

.post-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: var(--spacing-lg);
}

.post-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.post-excerpt {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-md);
  flex: 1;
}

.post-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  color: var(--text-light);
  font-size: 0.875rem;
}

.admin-dashboard {
  display: grid;
  grid-template-columns: 250px 1fr;
  min-height: calc(100vh - var(--header-height));
}

.admin-sidebar {
  background-color: var(--bg-secondary);
  padding: var(--spacing-lg);
  border-right: 1px solid var(--border-color);
}

.admin-sidebar-menu {
  list-style: none;
}

.admin-sidebar-item {
  margin-bottom: var(--spacing-md);
}

.admin-sidebar-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: 0.5rem;
  text-decoration: none;
  color: var(--text-primary);
  border-radius: var(--border-radius-sm);
  transition: background-color 0.2s ease;
}

.admin-sidebar-link:hover,
.admin-sidebar-link.active {
  background-color: var(--bg-primary);
  color: var(--primary-color);
}

.admin-main {
  padding: var(--spacing-lg);
  overflow-y: auto;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.stat-card {
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-sm);
  text-align: center;
}

.stat-value {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.stat-label {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

@media (max-width: 768px) {
  .grid-cols-2,
  .grid-cols-3,
  .grid-cols-4 {
    grid-template-columns: 1fr;
  }
  
  .hero-title {
    font-size: 2rem;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }
  
  .hero-actions {
    flex-direction: column;
    align-items: center;
  }
  
  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    flex-direction: column;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    z-index: 100;
  }
  
  .nav-menu.active {
    display: flex;
  }
  
  .mobile-menu-btn {
    display: block;
  }
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
  }
  
  .admin-dashboard {
    grid-template-columns: 1fr;
  }
  
  .admin-sidebar {
    display: none;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  .section {
    padding: var(--spacing-xl) 0;
  }
  
  .section-title {
    font-size: 1.5rem;
  }
  
  .hero {
    padding: 2rem 0;
  }
  
  .hero-title {
    font-size: 1.75rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
  }
}