* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f8f9fa;
            color: #333;
            line-height: 1.6;
        }
        
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* Promotional Banner */
        .promo-banner {
            background: linear-gradient(to right, #3a7bd5, #00d2ff);
            color: white;
            padding: 12px 0;
            text-align: center;
            font-weight: bold;
            font-size: 18px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        }
        
        /* Header */
        header {
            background-color: white;
            padding: 20px 0;
            box-shadow: 0 2px 15px rgba(0, 0, 0, 0.08);
        }
        
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .logo {
            font-size: 28px;
            font-weight: 700;
            color: #dc3545;
            display: flex;
            align-items: center;
        }
        
        .logo i {
            margin-right: 10px;
            color: #00d2ff;
        }
        
        /* Navigation */
        nav ul {
            display: flex;
            list-style: none;
        }
        
        nav ul li {
            margin-left: 25px;
        }
        
        nav ul li a {
            text-decoration: none;
            color: #555;
            font-weight: 500;
            transition: color 0.3s;
            display: flex;
            align-items: center;
        }
        
        nav ul li a i {
            margin-right: 8px;
            font-size: 16px;
        }
        
        nav ul li a:hover {
            color: #3a7bd5;
        }
        
        /* Main Content */
        .main-content {
            padding: 40px 0;
        }
        
        .section-header {
            text-align: center;
            margin-bottom: 40px;
        }
        
        .section-header h1 {
            font-size: 36px;
            color: #2c3e50;
            margin-bottom: 15px;
        }
        
        .section-header p {
            color: #7f8c8d;
            max-width: 800px;
            margin: 0 auto;
            font-size: 18px;
        }
        
        /* Courses Grid */
        .courses-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 30px;
            margin-top: 40px;
        }
        
        .course-card {
            background-color: white;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            transition: transform 0.3s, box-shadow 0.3s;
        }
        
        .course-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
        }
        
        .course-header {
            padding: 20px;
            background: linear-gradient(to right, #e74c3c, #ad4278);
            color: white;
        }
        
        .course-header h3 {
            font-size: 22px;
            margin-bottom: 5px;
        }
        
        .course-header p {
            font-size: 14px;
            opacity: 0.9;
        }
        
        .course-content {
            padding: 20px;
        }
        
        .course-content ul {
            list-style: none;
            margin-top: 15px;
        }
        
        .course-content ul li {
            padding: 8px 0;
            border-bottom: 1px solid #eee;
            display: flex;
            align-items: center;
        }
        
        .course-content ul li:last-child {
            border-bottom: none;
        }
        
        .course-content ul li i {
            color: #3a7bd5;
            margin-right: 10px;
        }
        
        .course-footer {
            padding: 15px 20px;
            background-color: #f8f9fa;
            border-top: 1px solid #eee;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .progress {
            font-size: 14px;
            color: #7f8c8d;
        }
        
        .progress.completed {
            color: #2ecc71;
        }
        
        .btn {
            background-color: #dc3545;
            color: white;
            border: none;
            padding: 8px 16px;
            border-radius: 5px;
            cursor: pointer;
            font-weight: 500;
            transition: background-color 0.3s;
        }
        
        .btn:hover {
            background-color: #2a6bc4;
        }
        
        /* Oxford 3000 Section */
        .oxford-section {
            background-color: white;
            border-radius: 10px;
            padding: 30px;
            margin-top: 40px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
        }
        
        .oxford-header {
            margin-bottom: 25px;
        }
        
        .oxford-header h2 {
            font-size: 28px;
            color: #2c3e50;
            margin-bottom: 10px;
        }
        
        .oxford-header p {
            color: #7f8c8d;
        }
        
        .lesson-list {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 15px;
        }
        
        .lesson-item {
            background-color: #f8f9fa;
            padding: 15px;
            border-radius: 8px;
            border-left: 4px solid #3a7bd5;
            display: flex;
            align-items: center;
            transition: background-color 0.3s;
        }
        
        .lesson-item:hover {
            background-color: #edf4ff;
        }
        
        .lesson-item i {
            color: #3a7bd5;
            margin-right: 10px;
            font-size: 18px;
        }
        
        .completed-lesson {
            border-left-color: #2ecc71;
        }
        
        .completed-lesson i {
            color: #2ecc71;
        }
        
        /* Footer */
        footer {
            background-color: #2c3e50;
            color: white;
            padding: 40px 0;
            margin-top: 60px;
        }
        
        .footer-content {
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
        }
        
        .footer-column {
            flex: 1;
            min-width: 250px;
            margin-bottom: 20px;
            padding-right: 20px;
        }
        
        .footer-column h4 {
            font-size: 18px;
            margin-bottom: 20px;
            color: #ecf0f1;
        }
        
        .footer-column ul {
            list-style: none;
        }
        
        .footer-column ul li {
            margin-bottom: 10px;
        }
        
        .footer-column ul li a {
            color: #bdc3c7;
            text-decoration: none;
            transition: color 0.3s;
        }
        
        .footer-column ul li a:hover {
            color: #3a7bd5;
        }
        
        .copyright {
            text-align: center;
            padding-top: 20px;
            margin-top: 20px;
            border-top: 1px solid #34495e;
            color: #bdc3c7;
            font-size: 14px;
        }
        
        /* Responsive Design */
        @media (max-width: 992px) {
            .header-content {
                flex-direction: column;
                text-align: center;
            }
            
            nav ul {
                margin-top: 20px;
                flex-wrap: wrap;
                justify-content: center;
            }
            
            nav ul li {
                margin: 5px 15px;
            }
            
            .section-header h1 {
                font-size: 32px;
            }
        }
        
        @media (max-width: 768px) {
            .courses-grid {
                grid-template-columns: 1fr;
            }
            
            .footer-column {
                min-width: 100%;
                padding-right: 0;
            }
        }