* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f5f7fa;
            color: #333;
            line-height: 1.6;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px;
        }
        
        header {
            background: linear-gradient(135deg, #1a2a6c, #2a3a7c);
            color: white;
            padding: 30px 0;
            text-align: center;
            border-radius: 0 0 10px 10px;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
            margin-bottom: 30px;
        }
        
        .logo {
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 15px;
        }
        
        .logo-icon {
            font-size: 2.5rem;
            margin-right: 15px;
        }
        
        /* Navigation Menu Styles */
        .main-nav {
            background: #fff;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            margin-bottom: 30px;
        }
        
        .nav-menu {
            display: flex;
            list-style: none;
            justify-content: center;
            flex-wrap: wrap;
        }
        
        .nav-menu li {
            margin: 0;
        }
        
        .nav-menu a {
            display: block;
            padding: 15px 25px;
            text-decoration: none;
            color: #333;
            font-weight: 500;
            transition: all 0.3s ease;
            border-bottom: 3px solid transparent;
        }
        
        .nav-menu a:hover {
            background-color: #f0f5ff;
            color: #1a2a6c;
            border-bottom: 3px solid #1a2a6c;
        }
        
        .nav-menu .current a {
            color: #1a2a6c;
            border-bottom: 3px solid #1a2a6c;
            background-color: #f0f5ff;
        }
        
        /* Responsive navigation */
        @media (max-width: 768px) {
            .nav-menu {
                flex-direction: column;
            }
            
            .nav-menu li {
                width: 100%;
                text-align: center;
            }
        }
        
        .professor-info {
            background: white;
            padding: 25px;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
            margin-bottom: 30px;
            display: flex;
            align-items: center;
            gap: 20px;
        }
        
        .professor-avatar {
            font-size: 4rem;
        }
        
        .dashboard-section {
            background: white;
            padding: 25px;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
            margin-bottom: 30px;
        }
        
        .section-title {
            font-size: 1.5rem;
            color: #1a2a6c;
            margin-bottom: 20px;
            padding-bottom: 10px;
            border-bottom: 2px solid #e0e7ff;
        }
        
        .admin-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 20px;
            flex-wrap: wrap;
            gap: 15px;
        }
        
        .admin-buttons {
            display: flex;
            gap: 10px;
            flex-wrap: wrap;
        }
        
        .btn {
            padding: 10px 20px;
            border: none;
            border-radius: 5px;
            text-decoration: none;
            font-size: 14px;
            cursor: pointer;
            transition: all 0.3s ease;
            display: inline-flex;
            align-items: center;
            gap: 5px;
        }
        
        .btn-primary {
            background: #007bff;
            color: white;
        }
        
        .btn-success {
            background: #28a745;
            color: white;
        }
        
        .btn-secondary {
            background: #6c757d;
            color: white;
        }
        
        .btn-danger {
            background: #dc3545;
            color: white;
        }
        
        .btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.2);
        }
        
        .success-message {
            background-color: #d4edda;
            color: #155724;
            padding: 15px;
            border-radius: 5px;
            border: 1px solid #c3e6cb;
            margin-bottom: 20px;
        }
        
        .error-message {
            background-color: #f8d7da;
            color: #721c24;
            padding: 15px;
            border-radius: 5px;
            border: 1px solid #f5c6cb;
            margin-bottom: 20px;
        }
        
        .info-message {
            background-color: #e2f0ff;
            border: 1px solid #b6d4fe;
            border-radius: 5px;
            padding: 15px;
            margin-bottom: 20px;
        }
        
        .current-semester-banner {
            background: #e7f3ff;
            padding: 15px;
            border-radius: 8px;
            margin-bottom: 20px;
            text-align: center;
            border: 2px solid #007bff;
        }
        
        .courses-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 20px;
            margin-top: 20px;
        }
        
        .course-card {
            background: white;
            border-radius: 10px;
            padding: 20px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.1);
            border-left: 4px solid #007bff;
            transition: all 0.3s ease;
        }
        
        .course-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.15);
        }
        
        .course-code {
            font-weight: bold;
            color: #007bff;
            font-size: 1.1rem;
        }
        
        .course-name {
            font-size: 1.2rem;
            margin: 10px 0;
            color: #2c3e50;
        }
        
        .course-description {
            color: #666;
            margin-bottom: 15px;
        }
        
        .course-meta {
            display: flex;
            justify-content: space-between;
            font-size: 0.9rem;
            color: #666;
        }
        
        .status.active {
            color: #28a745;
            font-weight: bold;
        }
        
        .modal {
            display: none;
            position: fixed;
            z-index: 1000;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0,0,0,0.5);
        }
        
        .modal-content {
            background-color: white;
            margin: 10% auto;
            padding: 30px;
            border-radius: 10px;
            width: 90%;
            max-width: 400px;
            position: relative;
        }
        
        .close {
            position: absolute;
            right: 15px;
            top: 15px;
            font-size: 24px;
            cursor: pointer;
            color: #666;
        }
        
        .form-group {
            margin-bottom: 20px;
        }
        
        .form-group label {
            display: block;
            margin-bottom: 5px;
            font-weight: bold;
        }
        
        .form-group input {
            width: 100%;
            padding: 10px;
            border: 1px solid #ddd;
            border-radius: 5px;
            font-size: 14px;
        }
        
        .debug-info {
            background: #f8f9fa;
            padding: 10px;
            margin: 10px 0;
            border-left: 4px solid #007bff;
            font-family: monospace;
            font-size: 12px;
        }
        /* Add to courses.css */
.course-card.no-access {
    opacity: 0.7;
    background: #f8f9fa;
}

.access-badge {
    padding: 5px 10px;
    border-radius: 15px;
    font-size: 0.8em;
    font-weight: bold;
    margin: 10px 0;
}

.access-badge.granted {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.access-badge.denied {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.course-access {
    text-align: center;
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px solid #eee;
}
/* Course Level Styles */
.course-level-filter {
    margin-bottom: 20px;
    text-align: right;
}

.course-level-filter label {
    font-weight: bold;
    margin-right: 10px;
}

.course-level-filter select {
    padding: 8px 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    background: white;
}

.course-header {
    display: flex;
    justify-content: between;
    align-items: flex-start;
    margin-bottom: 10px;
    gap: 10px;
}

.course-level-badge {
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 0.8em;
    font-weight: bold;
    white-space: nowrap;
}

.course-level-badge.undergraduate {
    background-color: #e3f2fd;
    color: #1976d2;
    border: 1px solid #bbdefb;
}

.course-level-badge.post-graduate {
    background-color: #f3e5f5;
    color: #7b1fa2;
    border: 1px solid #e1bee7;
}

.course-professor, .course-credits {
    font-size: 0.9em;
    color: #666;
    margin: 5px 0;
}

.course-professor i, .course-credits i {
    margin-right: 5px;
    width: 16px;
}

/* Course Statistics */
.course-stats {
    margin-top: 20px;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 8px;
    text-align: center;
    border-left: 4px solid #007bff;
}

.stats-info {
    font-weight: bold;
    color: #495057;
}

.stats-info i {
    margin-right: 8px;
    color: #007bff;
}