:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --dark-bg: #1f2937;
    --light-bg: #f9fafb;
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--light-bg);
    color: #374151;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    color: #111827;
}

.display-5 {
    font-weight: 800;
}

.card {
    border: none;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
    overflow: hidden;
}

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

.card-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    font-weight: 600;
}

.card-body {
    padding: 1.5rem;
}

.btn {
    border-radius: 8px;
    font-weight: 600;
    padding: 0.625rem 1.25rem;
    transition: all 0.3s ease;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    box-shadow: 0 4px 6px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), #3730a3);
    box-shadow: 0 6px 12px rgba(99, 102, 241, 0.4);
    transform: translateY(-2px);
}

.btn-success {
    background: linear-gradient(135deg, var(--success-color), #059669);
    box-shadow: 0 4px 6px rgba(16, 185, 129, 0.3);
}

.btn-success:hover {
    background: linear-gradient(135deg, #059669, #047857);
    box-shadow: 0 6px 12px rgba(16, 185, 129, 0.4);
    transform: translateY(-2px);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger-color), #dc2626);
    box-shadow: 0 4px 6px rgba(239, 68, 68, 0.3);
}

.btn-danger:hover {
    background: linear-gradient(135deg, #dc2626, #b91c1c);
    box-shadow: 0 6px 12px rgba(239, 68, 68, 0.4);
    transform: translateY(-2px);
}

.btn-outline-secondary {
    border: 2px solid #d1d5db;
    color: #6b7280;
}

.btn-outline-secondary:hover {
    background-color: #f3f4f6;
    border-color: #9ca3af;
    color: #374151;
}

.form-control,
.form-select {
    border-radius: 8px;
    border: 2px solid #e5e7eb;
    padding: 0.75rem 1rem;
    transition: all 0.3s ease;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-label {
    font-weight: 600;
    color: #374151;
    margin-bottom: 0.5rem;
}

.navbar {
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    padding: 1rem 0;
}

.navbar-brand {
    font-weight: 800;
    font-size: 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-link {
    font-weight: 500;
    transition: color 0.3s ease;
}

.badge {
    border-radius: 6px;
    padding: 0.5rem 0.75rem;
    font-weight: 600;
}

.bg-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark)) !important;
}

.bg-success {
    background: linear-gradient(135deg, var(--success-color), #059669) !important;
}

.alert {
    border-radius: 10px;
    border: none;
    padding: 1rem 1.25rem;
}

.alert-info {
    background-color: #dbeafe;
    color: #1e40af;
}

.alert-danger {
    background-color: #fee2e2;
    color: #991b1b;
}

.alert-success {
    background-color: #d1fae5;
    color: #065f46;
}

.hero-section {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 4rem 0;
    border-radius: 16px;
    margin-bottom: 2rem;
}

.hero-section h1 {
    color: white;
    font-weight: 800;
}

.stats-card {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--card-shadow);
    text-align: center;
}

.stats-card h3 {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stats-card p {
    color: #6b7280;
    font-weight: 500;
    margin: 0;
}

.pagination-controls {
    margin-top: 2rem;
    text-align: center;
}

.pagination-controls button {
    margin: 0 0.5rem;
}

.list-group-item {
    border: 1px solid #e5e7eb;
    border-radius: 8px !important;
    margin-bottom: 0.75rem;
    transition: all 0.3s ease;
}

.list-group-item:hover {
    background-color: #f9fafb;
    box-shadow: var(--card-shadow);
}

.breadcrumb {
    background-color: transparent;
    padding: 0;
    margin-bottom: 1.5rem;
}

.breadcrumb-item a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.breadcrumb-item a:hover {
    text-decoration: underline;
}

.modal-content {
    border-radius: 16px;
    border: none;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

.modal-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-top-left-radius: 16px;
    border-top-right-radius: 16px;
    border: none;
}

.modal-title {
    font-weight: 700;
}

.btn-close {
    filter: brightness(0) invert(1);
}

.text-gradient {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.rounded-custom {
    border-radius: 12px;
}

@media (max-width: 768px) {
    .hero-section {
        padding: 2rem 0;
    }

    .card-body {
        padding: 1rem;
    }

    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }
}

.search-box-wrapper {
    position: relative;
}

.search-input {
    font-size: 1.1rem;
    padding: 1rem 1.5rem;
}

.search-input:focus {
    box-shadow: none !important;
}

.input-group-lg .input-group-text {
    padding: 1rem 1.25rem;
}

.input-group-lg .btn {
    padding: 1rem 2rem;
    font-size: 1rem;
}

.bg-gradient {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color)) !important;
}

.card.sticky-top {
    transition: all 0.3s ease;
}

.btn-outline-light:hover {
    background-color: rgba(255, 255, 255, 0.2);
    border-color: white;
}

#course-count {
    font-size: 0.95rem;
    font-weight: 500;
}