:root {
  /* Dark Theme (Default) */
  --primary-color: #ffd700;
  --secondary-color: #ffa500;
  --background-color: #1a1a1a;
  --surface-color: #2d2d2d;
  --text-color: #ffffff;
  --text-secondary: #cccccc;
  --border-color: #404040;
  --shadow: rgba(255, 215, 0, 0.1);
  --gradient: linear-gradient(135deg, #ffd700, #ffa500);
}

[data-theme="light"] {
  /* Light Theme */
  --primary-color: #ffd700;
  --secondary-color: #ffa500;
  --background-color: #ffffff;
  --surface-color: #f8f9fa;
  --text-color: #333333;
  --text-secondary: #666666;
  --border-color: #e0e0e0;
  --shadow: rgba(0, 0, 0, 0.1);
  --gradient: linear-gradient(135deg, #ffd700, #ffa500);
}

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

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--background-color);
  color: var(--text-color);
  line-height: 1.6;
  transition: all 0.3s ease;
}

/* Theme Toggle - Nằm trong navbar */
.theme-toggle-btn-nav {
  width: auto !important;
  height: auto !important;
  border-radius: 8px !important;
  padding: 10px 15px !important;
  color: var(--text-color) !important;
  font-weight: 500 !important;
  transition: all 0.3s ease;
  display: flex !important;
  align-items: center !important;
  gap: 8px;
}

.theme-toggle-btn-nav:hover {
  color: var(--primary-color) !important;
  background: rgba(255, 215, 0, 0.1) !important;
  transform: none !important;
}

.theme-toggle-btn-nav i {
  font-size: 16px;
}

/* Admin Header */
.admin-header {
  background: var(--surface-color);
  border-bottom: 3px solid var(--primary-color);
  box-shadow: 0 2px 15px var(--shadow);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.navbar-brand {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color) !important;
  text-decoration: none;
}

.navbar-brand i {
  margin-right: 10px;
}

.navbar-nav .nav-link {
  color: var(--text-color) !important;
  font-weight: 500;
  transition: all 0.3s ease;
  padding: 10px 15px;
  border-radius: 8px;
}

.navbar-nav .nav-link:hover {
  color: var(--primary-color) !important;
  background: rgba(255, 215, 0, 0.1);
}

/* Sidebar */
.sidebar {
  background: var(--surface-color);
  min-height: calc(100vh - 76px);
  border-right: 2px solid var(--border-color);
  padding: 0;
}

.sidebar-content {
  padding: 30px 20px;
}

.sidebar-title {
  color: var(--primary-color);
  font-weight: bold;
  margin-bottom: 30px;
  padding-bottom: 15px;
  border-bottom: 2px solid var(--border-color);
}

.sidebar-title i {
  margin-right: 10px;
}

.sidebar .nav-link {
  color: var(--text-color);
  padding: 15px 20px;
  margin-bottom: 10px;
  border-radius: 10px;
  transition: all 0.3s ease;
  border: 2px solid transparent;
}

.sidebar .nav-link:hover,
.sidebar .nav-link.active {
  background: var(--gradient);
  color: #333 !important;
  transform: translateX(5px);
  border-color: var(--primary-color);
}

.sidebar .nav-link i {
  margin-right: 10px;
  width: 20px;
}

/* Main Content */
.main-content {
  padding: 30px;
  background: var(--background-color);
  min-height: calc(100vh - 76px);
}

/* Cards */
.card {
  background: var(--surface-color);
  border: 2px solid var(--border-color);
  border-radius: 15px;
  box-shadow: 0 8px 25px var(--shadow);
  margin-bottom: 30px;
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 35px var(--shadow);
}

.card-header {
  background: var(--gradient);
  color: #333;
  border-bottom: 2px solid var(--border-color);
  border-radius: 13px 13px 0 0 !important;
  padding: 20px;
}

.card-header h4 {
  margin: 0;
  font-weight: bold;
}

.card-header i {
  margin-right: 10px;
}

.card-body {
  padding: 30px;
}

/* Form Elements */
.form-label {
  color: var(--text-color);
  font-weight: 600;
  margin-bottom: 8px;
}

.form-control,
.form-select {
  background: var(--background-color);
  border: 2px solid var(--border-color);
  color: var(--text-color);
  border-radius: 10px;
  padding: 12px 15px;
  transition: all 0.3s ease;
}

.form-control:focus,
.form-select:focus {
  background: var(--background-color);
  border-color: var(--primary-color);
  color: var(--text-color);
  box-shadow: 0 0 0 0.2rem rgba(255, 215, 0, 0.25);
}

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

/* Buttons */
.btn {
  border-radius: 10px;
  padding: 12px 25px;
  font-weight: 600;
  transition: all 0.3s ease;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--gradient);
  border-color: var(--primary-color);
  color: #333;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(255, 215, 0, 0.4);
  color: #333;
}

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

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

.btn-outline-primary {
  border-color: var(--primary-color);
  color: var(--primary-color);
}

.btn-outline-primary:hover {
  background: var(--primary-color);
  color: #333;
}

.btn-outline-danger {
  border-color: #dc3545;
  color: #dc3545;
}

.btn-outline-danger:hover {
  background: #dc3545;
  color: white;
}

/* Table */
.table {
  color: var(--text-color);
  background: var(--surface-color);
}

.table th {
  background: var(--background-color);
  color: var(--primary-color);
  border-color: var(--border-color);
  font-weight: bold;
  padding: 15px;
}

.table td {
  border-color: var(--border-color);
  padding: 15px;
  vertical-align: middle;
}

.table-hover tbody tr:hover {
  background: rgba(255, 215, 0, 0.1);
}

.banner-thumbnail {
  width: 80px;
  height: 50px;
  object-fit: cover;
  border-radius: 8px;
  border: 2px solid var(--border-color);
}

/* Badges */
.badge {
  padding: 8px 12px;
  border-radius: 20px;
  font-weight: 600;
}

.bg-success {
  background: #28a745 !important;
}

.bg-secondary {
  background: #6c757d !important;
}

.bg-info {
  background: var(--primary-color) !important;
  color: #333 !important;
}

/* Alerts */
.alert {
  border-radius: 10px;
  border: 2px solid;
  padding: 15px 20px;
}

.alert-success {
  background: rgba(40, 167, 69, 0.1);
  border-color: #28a745;
  color: #28a745;
}

.alert i {
  margin-right: 10px;
}

/* Form Card */
.form-card {
  border: 3px solid var(--primary-color);
}

.form-card .card-header {
  background: var(--primary-color);
  color: #333;
}

/* Responsive Design */
@media (max-width: 768px) {
  .main-content {
    padding: 15px;
  }

  .sidebar {
    position: fixed;
    top: 76px;
    left: -100%;
    width: 280px;
    z-index: 1000;
    transition: left 0.3s ease;
  }

  .sidebar.show {
    left: 0;
  }

  .theme-toggle-container {
    top: 10px;
    right: 10px;
  }

  .theme-toggle-btn {
    width: 40px;
    height: 40px;
    font-size: 16px;
  }

  .card-body {
    padding: 20px;
  }

  .table-responsive {
    border-radius: 10px;
  }
}

/* Smooth transitions for theme switching */
* {
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}