* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f5f7fa;
            color: #333;
        }
        
        .container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 20px;
        }
        
        header {
            background: linear-gradient(135deg, #1a2a6c, #2a3a7c);
            color: white;
            padding: 20px 0;
            border-radius: 0 0 10px 10px;
            margin-bottom: 30px;
        }
        
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .user-info {
            text-align: right;
        }
        
        .user-info .student-name {
            font-size: 1.2rem;
            font-weight: 600;
        }
        
        .logout-btn {
            background: #ef4444;
            color: white;
            border: none;
            padding: 8px 15px;
            border-radius: 5px;
            cursor: pointer;
            text-decoration: none;
            display: inline-block;
            margin-top: 5px;
        }
        
        .logout-btn:hover {
            background: #dc2626;
        }
        
        .dashboard-container {
            display: flex;
            gap: 20px;
        }
        
        .sidebar {
            width: 250px;
            background: white;
            border-radius: 10px;
            padding: 20px;
            box-shadow: 0 0 10px rgba(0,0,0,0.1);
        }
        
        .main-content {
            flex: 1;
            background: white;
            border-radius: 10px;
            padding: 30px;
            box-shadow: 0 0 10px rgba(0,0,0,0.1);
        }
        
        .sidebar h3 {
            color: #1a2a6c;
            margin-bottom: 20px;
            padding-bottom: 10px;
            border-bottom: 2px solid #e5e7eb;
        }
        
        .course-list {
            list-style: none;
        }
        
        .course-item {
            padding: 12px 15px;
            margin-bottom: 8px;
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.3s;
            border-left: 3px solid transparent;
        }
        
        .course-item:hover {
            background-color: #e8f4ff;
        }
        
        .course-item.active {
            background-color: #e8f4ff;
            border-left-color: #3b82f6;
            font-weight: 500;
        }
        
        .course-item .course-code {
            font-weight: 600;
            color: #1a2a6c;
        }
        
        .course-item .course-name {
            font-size: 0.9rem;
            color: #6b7280;
            margin-top: 3px;
        }
        
        .welcome-card {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            padding: 25px;
            border-radius: 10px;
            margin-bottom: 30px;
        }
        
        .welcome-card h2 {
            margin-bottom: 10px;
        }
        
        .tabs {
            display: flex;
            border-bottom: 2px solid #e5e7eb;
            margin-bottom: 25px;
            flex-wrap: wrap;
        }
        
        .tab {
            padding: 12px 25px;
            cursor: pointer;
            border-bottom: 3px solid transparent;
            font-weight: 500;
            transition: all 0.3s;
            color: #6b7280;
        }
        
        .tab:hover {
            color: #374151;
            background-color: #f9fafb;
        }
        
        .tab.active {
            color: #3b82f6;
            border-bottom-color: #3b82f6;
            background-color: #eff6ff;
        }
        
        .tab-content {
            display: none;
        }
        
        .tab-content.active {
            display: block;
        }
        
        .materials-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 20px;
        }
        
        .material-card {
            border: 1px solid #e5e7eb;
            border-radius: 8px;
            padding: 20px;
            transition: all 0.3s;
        }
        
        .material-card:hover {
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        
        .material-title {
            font-weight: 600;
            margin-bottom: 10px;
            color: #1a2a6c;
        }
        
        .material-meta {
            font-size: 0.9rem;
            color: #6b7280;
            margin-bottom: 15px;
        }
        
        .download-btn {
            background: #10b981;
            color: white;
            border: none;
            padding: 8px 15px;
            border-radius: 5px;
            cursor: pointer;
            text-decoration: none;
            display: inline-block;
        }
        
        .download-btn:hover {
            background: #059669;
        }
        
        .announcement-card {
            border-left: 4px solid #3b82f6;
            background-color: #f0f9ff;
            padding: 20px;
            border-radius: 6px;
            margin-bottom: 20px;
        }
        
        .announcement-title {
            font-weight: 600;
            margin-bottom: 10px;
            color: #1a2a6c;
        }
        
        .announcement-date {
            color: #6b7280;
            font-size: 0.9rem;
            margin-top: 10px;
        }
        
        .assignment-card {
            border: 1px solid #e5e7eb;
            border-radius: 8px;
            padding: 20px;
            margin-bottom: 20px;
        }
        
        .assignment-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 15px;
        }
        
        .assignment-title {
            font-weight: 600;
            color: #1a2a6c;
        }
        
        .due-date {
            color: #ef4444;
            font-weight: 500;
        }
        
        .assignment-status {
            padding: 5px 10px;
            border-radius: 20px;
            font-size: 0.9rem;
            font-weight: 500;
        }
        
        .status-submitted {
            background-color: #d1fae5;
            color: #065f46;
        }
        
        .status-pending {
            background-color: #fef3c7;
            color: #92400e;
        }
        
        .grade-badge {
            background-color: #3b82f6;
            color: white;
            padding: 5px 10px;
            border-radius: 20px;
            font-weight: 500;
        }
        
        .attendance-table {
            width: 100%;
            border-collapse: collapse;
        }
        
        .attendance-table th,
        .attendance-table td {
            padding: 12px;
            text-align: left;
            border-bottom: 1px solid #e5e7eb;
        }
        
        .attendance-table th {
            background-color: #f9fafb;
            font-weight: 600;
        }
        
        .present {
            color: #10b981;
            font-weight: 500;
        }
        
        .absent {
            color: #ef4444;
            font-weight: 500;
        }
        
        .paper-card {
            border: 1px solid #e5e7eb;
            border-radius: 8px;
            padding: 20px;
            margin-bottom: 20px;
        }
        
        .paper-title {
            font-weight: 600;
            margin-bottom: 10px;
            color: #1a2a6c;
        }
        
        .paper-author {
            color: #6b7280;
            font-style: italic;
        }
        
        .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;
        }
        
        .empty-state {
            text-align: center;
            padding: 40px;
            color: #6b7280;
        }
        
        .empty-state i {
            font-size: 3rem;
            color: #d1d5db;
            margin-bottom: 15px;
        }
        
        .submit-form {
            background-color: #f9fafb;
            padding: 20px;
            border-radius: 8px;
            margin-top: 20px;
        }
        
        .file-input {
            margin: 15px 0;
        }
        
        .submit-btn {
            background: #3b82f6;
            color: white;
            border: none;
            padding: 10px 20px;
            border-radius: 5px;
            cursor: pointer;
        }
        
        .submit-btn:hover {
            background: #2563eb;
        }
        
        @media (max-width: 1024px) {
            .dashboard-container {
                flex-direction: column;
            }
            
            .sidebar {
                width: 100%;
            }
        }
        /* Footer Styles */
.site-footer {
    background-color: #1e293b;
    color: #cbd5e1;
    padding: 20px 0;
    margin-top: 40px;
    border-top: 3px solid #3b82f6;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.footer-left .copyright {
    font-size: 0.9rem;
    color: #94a3b8;
    margin: 0;
}

.footer-right .footer-links {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 0;
    font-size: 0.9rem;
}

.footer-link {
    color: #e2e8f0;
    text-decoration: none;
    transition: color 0.3s ease;
    display: flex;
    align-items: center;
    gap: 5px;
}

.footer-link:hover {
    color: #60a5fa;
    text-decoration: underline;
}

.separator {
    color: #475569;
}

/* Responsive footer */
@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        text-align: center;
        gap: 10px;
    }
    
    .footer-right .footer-links {
        justify-content: center;
        flex-wrap: wrap;
    }
}