* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f0f8ff;
            color: #333;
            line-height: 1.6;
            padding: 20px;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            background-image: linear-gradient(to bottom right, #f0f8ff, #e6f7ff);
        }
        
        .container {
            max-width: 1000px;
            width: 100%;
            background-color: white;
            border-radius: 20px;
            box-shadow: 0 15px 35px rgba(0, 104, 179, 0.1);
            padding: 40px;
            margin: 20px;
            border: 1px solid #e1f5fe;
        }
        
        .header {
            text-align: center;
            margin-bottom: 40px;
            padding-bottom: 25px;
            border-bottom: 2px solid #e3f2fd;
        }
        
        h1 {
            color: #0066cc;
            margin-bottom: 15px;
            font-size: 2.5rem;
            text-shadow: 1px 1px 3px rgba(0,0,0,0.1);
        }
        
        .subtitle {
            color: #5a6c7d;
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto;
        }
        
        .school-name {
            color: #d32f2f;
            font-weight: bold;
        }
        
        .button-container {
            display: flex;
            justify-content: center;
            margin: 40px 0;
        }
        
        .main-button {
            background: linear-gradient(135deg, #0066cc, #004d99);
            color: white;
            border: none;
            padding: 22px 50px;
            font-size: 1.4rem;
            border-radius: 60px;
            cursor: pointer;
            display: flex;
            align-items: center;
            gap: 15px;
            box-shadow: 0 8px 20px rgba(0, 102, 204, 0.3);
            transition: all 0.4s ease;
            font-weight: 700;
            letter-spacing: 0.5px;
        }
        
        .main-button:hover {
            transform: translateY(-5px);
            box-shadow: 0 12px 25px rgba(0, 102, 204, 0.4);
            background: linear-gradient(135deg, #0073e6, #0059b3);
        }
        
        .main-button i {
            font-size: 1.6rem;
        }
        
        .submenu {
            display: none;
            background-color: white;
            border-radius: 20px;
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
            padding: 30px;
            margin-top: 30px;
            animation: fadeIn 0.5s ease-out;
            border: 1px solid #e1f5fe;
        }
        
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(15px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        .submenu-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 30px;
            padding-bottom: 20px;
            border-bottom: 2px solid #e3f2fd;
        }
        
        .submenu-title {
            color: #0066cc;
            font-size: 1.8rem;
            font-weight: 700;
        }
        
        .close-btn {
            background: #ffebee;
            border: none;
            color: #d32f2f;
            font-size: 1.5rem;
            cursor: pointer;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s;
        }
        
        .close-btn:hover {
            background: #ffcdd2;
            transform: rotate(90deg);
        }
        
        .options-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
            gap: 25px;
        }
        
        .option-card {
            background-color: #f8fbff;
            border-radius: 15px;
            padding: 30px 20px;
            text-align: center;
            cursor: pointer;
            transition: all 0.4s ease;
            border: 2px solid transparent;
            text-decoration: none;
            display: block;
            color: inherit;
        }
        
        .option-card:hover {
            transform: translateY(-8px);
            border-color: #0066cc;
            box-shadow: 0 12px 20px rgba(0, 102, 204, 0.15);
            background-color: #f0f7ff;
        }
        
        .option-icon {
            width: 70px;
            height: 70px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
            font-size: 2rem;
            color: white;
        }
        
        .inicial-icon {
            background: linear-gradient(135deg, #4CAF50, #2E7D32);
        }
        
        .preparatoria-icon {
            background: linear-gradient(135deg, #FF9800, #EF6C00);
        }
        
        .basica-icon {
            background: linear-gradient(135deg, #2196F3, #0D47A1);
        }
        
        .bachillerato-icon {
            background: linear-gradient(135deg, #9C27B0, #6A1B9A);
        }
        
        .option-title {
            font-size: 1.4rem;
            font-weight: 700;
            color: #0066cc;
            margin-bottom: 10px;
        }
        
        .option-description {
            color: #5a6c7d;
            font-size: 0.95rem;
            line-height: 1.5;
            margin-bottom: 15px;
            min-height: 40px;
        }
        
        .link-info {
            font-size: 0.85rem;
            color: #2196F3;
            background-color: #e3f2fd;
            padding: 8px 12px;
            border-radius: 20px;
            display: inline-block;
            margin-top: 10px;
        }
        
        .instructions {
            background-color: #f0f7ff;
            border-left: 5px solid #0066cc;
            padding: 20px;
            margin-top: 40px;
            border-radius: 10px;
        }
        
        .instructions h3 {
            color: #0066cc;
            margin-bottom: 10px;
            font-size: 1.3rem;
        }
        
        .instructions p {
            color: #5a6c7d;
            margin-bottom: 10px;
        }
        
        .warning {
            background-color: #fff3e0;
            border-left: 5px solid #FF9800;
            padding: 15px;
            margin-top: 30px;
            border-radius: 10px;
        }
        
        .warning h4 {
            color: #EF6C00;
            margin-bottom: 8px;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .footer {
            margin-top: 40px;
            text-align: center;
            color: #5a6c7d;
            font-size: 0.9rem;
            padding-top: 20px;
            border-top: 1px solid #e1f5fe;
            width: 100%;
        }
        
        @media (max-width: 900px) {
            .options-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }
        
        @media (max-width: 768px) {
            .container {
                padding: 25px;
            }
            
            h1 {
                font-size: 2rem;
            }
            
            .options-grid {
                grid-template-columns: 1fr;
            }
            
            .main-button {
                padding: 18px 35px;
                font-size: 1.2rem;
            }
        }
        
        @media (max-width: 480px) {
            body {
                padding: 10px;
            }
            
            .container {
                padding: 20px 15px;
            }
            
            .submenu {
                padding: 20px 15px;
            }
        }