:root {
            --primary: #4a6fa5;
            --secondary: #166088;
            --accent: #4fc3f7;
            --dark: #0a1128;
            --light: #f8f9fa;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: var(--light);
            color: var(--dark);
            line-height: 1.6;
        }
        
      
        
        
        .logo {
            font-size: 1.8rem;
            font-weight: 700;
            display: flex;
            align-items: center;
        }
        
        .logo i {
            margin-right: 10px;
            color: var(--accent);
        }
        
        nav ul {
            display: flex;
            list-style: none;
        }
        
        nav ul li {
            margin-left: 2rem;
        }
        
        nav ul li a {
            color: white;
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s ease;
        }
        
        nav ul li a:hover {
            color: var(--accent);
        }
        
        .auth-buttons button {
            padding: 0.5rem 1.2rem;
            border-radius: 5px;
            border: none;
            cursor: pointer;
            font-weight: 600;
            transition: all 0.3s ease;
        }
        
        .login-btn {
            background: transparent;
            color: white;
            border: 2px solid white;
            margin-right: 1rem;
        }
        
        .login-btn:hover {
            background: rgba(255,255,255,0.1);
        }
        
        .register-btn {
            background: var(--accent);
            color: var(--dark);
        }
        
        .register-btn:hover {
            background: #3ab4e0;
        }
        
        .hero {
            background: url('https://images.unsplash.com/photo-1550751827-4bd374c3f58b?ixlib=rb-4.0.3&auto=format&fit=crop&w=1350&q=80') no-repeat center center/cover;
            height: 70vh;
            display: flex;
            align-items: center;
            padding: 0 5%;
            position: relative;
        }
        
        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0,0,0,0.6);
        }
        
        .hero-content {
            position: relative;
            z-index: 1;
            color: white;
            max-width: 600px;
        }
        
        .hero h1 {
            font-size: 3rem;
            margin-bottom: 1rem;
            line-height: 1.2;
        }
        
        .hero p {
            font-size: 1.2rem;
            margin-bottom: 2rem;
        }
        
        .cta-button {
            display: inline-block;
            padding: 0.8rem 1.8rem;
            background: var(--accent);
            color: var(--dark);
            text-decoration: none;
            border-radius: 5px;
            font-weight: 600;
            transition: all 0.3s ease;
        }
        
        .cta-button:hover {
            background: #3ab4e0;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.2);
        }
        
        .courses-section {
            padding: 5rem 5%;
        }
        
        .section-title {
            text-align: center;
            margin-bottom: 3rem;
        }
        
        .section-title h2 {
            font-size: 2.5rem;
            color: var(--secondary);
            margin-bottom: 1rem;
        }
        
        .section-title p {
            color: #666;
            max-width: 700px;
            margin: 0 auto;
        }
        
        .courses-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 2rem;
        }
        
        .course-card {
            background: white;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            transition: all 0.3s ease;
        }
        
        .course-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        
        .course-image {
            height: 200px;
            overflow: hidden;
        }
        
        .course-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        
        .course-card:hover .course-image img {
            transform: scale(1.1);
        }
        
        .course-content {
            padding: 1.5rem;
        }
        
        .course-category {
            display: inline-block;
            padding: 0.3rem 0.8rem;
            background: var(--accent);
            color: var(--dark);
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 600;
            margin-bottom: 0.8rem;
        }
        
        .course-title {
            font-size: 1.3rem;
            margin-bottom: 0.8rem;
            color: var(--dark);
        }
        
        .course-description {
            color: #666;
            margin-bottom: 1.2rem;
            font-size: 0.95rem;
        }
        
        .course-meta {
            display: flex;
            justify-content: space-between;
            align-items: center;
            color: #666;
            font-size: 0.9rem;
        }
        
        .enroll-btn {
            display: block;
            width: 100%;
            padding: 0.8rem;
            background: var(--primary);
            color: white;
            border: none;
            border-radius: 5px;
            cursor: pointer;
            font-weight: 600;
            transition: all 0.3s ease;
            text-align: center;
            text-decoration: none;
        }
        
        .enroll-btn:hover {
            background: var(--secondary);
        }
        
        /* Modal Styles */
        .modal {
            display: none;
            position: fixed;
            z-index: 100;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            overflow: auto;
            background-color: rgba(0,0,0,0.5);
        }
        
        .modal-content {
            background-color: white;
            margin: 10% auto;
            padding: 2rem;
            border-radius: 10px;
            width: 90%;
            max-width: 500px;
            box-shadow: 0 5px 30px rgba(0,0,0,0.3);
            position: relative;
            animation: modalopen 0.5s;
        }
        
        @keyframes modalopen {
            from {opacity: 0; transform: translateY(-50px);}
            to {opacity: 1; transform: translateY(0);}
        }
        
        .close {
            position: absolute;
            top: 1rem;
            right: 1.5rem;
            font-size: 1.5rem;
            color: #aaa;
            cursor: pointer;
        }
        
        .close:hover {
            color: #333;
        }
        
        .modal h2 {
            margin-bottom: 1.5rem;
            color: var(--primary);
            text-align: center;
        }
        
        .form-group {
            margin-bottom: 1.2rem;
        }
        
        .form-group label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 500;
        }
        
        .form-group input {
            width: 100%;
            padding: 0.8rem;
            border: 1px solid #ddd;
            border-radius: 5px;
            font-size: 1rem;
        }
        
        .form-group input:focus {
            outline: none;
            border-color: var(--accent);
        }
        
        .submit-btn {
            width: 100%;
            padding: 0.8rem;
            background: var(--primary);
            color: white;
            border: none;
            border-radius: 5px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
        }
        
        .submit-btn:hover {
            background: var(--secondary);
        }
        
        .form-footer {
            text-align: center;
            margin-top: 1rem;
            font-size: 0.9rem;
        }
        
        .form-footer a {
            color: var(--primary);
            text-decoration: none;
            font-weight: 500;
        }
        
        .form-footer a:hover {
            text-decoration: underline;
        }
        
        .tab-container {
            display: flex;
            margin-bottom: 1.5rem;
            border-bottom: 1px solid #ddd;
        }
        
        .tab {
            padding: 0.8rem 1.5rem;
            cursor: pointer;
            font-weight: 500;
            color: #666;
            border-bottom: 3px solid transparent;
        }
        
        .tab.active {
            color: var(--primary);
            border-bottom: 3px solid var(--primary);
        }
        
        .tab-content {
            display: none;
        }
        
        .tab-content.active {
            display: block;
        }
        
        footer {
            background: var(--dark);
            color: white;
            padding: 3rem 5%;
            text-align: center;
        }
        
        .footer-content {
            max-width: 1200px;
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
            text-align: left;
        }
        
        .footer-column h3 {
            margin-bottom: 1.5rem;
            font-size: 1.2rem;
        }
        
        .footer-column ul {
            list-style: none;
        }
        
        .footer-column ul li {
            margin-bottom: 0.8rem;
        }
        
        .footer-column ul li a {
            color: #ccc;
            text-decoration: none;
            transition: all 0.3s ease;
        }
        
        .footer-column ul li a:hover {
            color: var(--accent);
        }
        
        .social-links {
            display: flex;
            gap: 1rem;
            margin-top: 1rem;
        }
        
        .social-links a {
            color: white;
            font-size: 1.2rem;
            transition: all 0.3s ease;
        }
        
        .social-links a:hover {
            color: var(--accent);
        }
        
        .copyright {
            margin-top: 3rem;
            padding-top: 1.5rem;
            border-top: 1px solid rgba(255,255,255,0.1);
            font-size: 0.9rem;
            color: #aaa;
        }
        
        .scroll-up-btn {
            position: fixed;
            bottom: 40px;
            right: 40px;
            z-index: 999;
            width: 48px;
            height: 48px;
            background: var(--primary);
            color: #fff;
            border: none;
            border-radius: 50%;
            box-shadow: 0 4px 16px rgba(0,0,0,0.18);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.3s, background 0.2s;
        }
        .scroll-up-btn.show {
            opacity: 1;
            pointer-events: auto;
        }
        .scroll-up-btn:hover {
            background: var(--secondary);
            color: #fff;
            box-shadow: 0 8px 24px rgba(0,0,0,0.22);
        }
        
        @media (max-width: 768px) {
           
            
            
            nav ul {
                margin: 1rem 0;
            }
            
            nav ul li {
                margin: 0 0.5rem;
            }
            
            .hero {
                height: 60vh;
                text-align: center;
            }
            
            .hero h1 {
                font-size: 2.2rem;
            }
            
            .hero p {
                font-size: 1rem;
            }
        }