:root {
            --primary-color: #4a6fa5;
            --secondary-color: #166088;
            --accent-color: #4fc3f7;
            --light-color: #f8f9fa;
            --dark-color: #343a40;
            --success-color: #28a745;
            --warning-color: #ffc107;
            --danger-color: #dc3545;
        }
        
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        .container {
            max-width: 1000px;
            margin: 0 auto;
            padding: 20px;
        }
        
        .subtitle {
            color: var(--secondary-color);
            font-weight: 300;
        }
        
        .main-content {
            display: flex;
            flex-direction: column;
            gap: 30px;
        }
        
        .card {
            background-color: white;
            border-radius: 8px;
            box-shadow: 0 3px 8px #333;
            padding: 25px;
        }
        
        .card-title {
            color: var(--primary-color);
            margin-bottom: 15px;
            font-size: 1.5rem;
        }
        
        .form-group {
            margin-bottom: 20px;
        }
        
        label {
            display: block;
            margin-bottom: 8px;
            font-weight: 500;
            color: var(--dark-color);
        }
        
        input[type="file"] {
            width: 100%;
            padding: 10px;
            border: 1px solid #ddd;
            border-radius: 4px;
            font-size: 16px;
            transition: border-color 0.3s;
        }
        
        .btn {
            display: inline-block;
            background-color: var(--primary-color);
            color: white;
            padding: 12px 24px;
            border: none;
            border-radius: 4px;
            cursor: pointer;
            font-size: 16px;
            font-weight: 500;
            text-align: center;
            transition: background-color 0.3s, transform 0.2s;
        }
        
        .btn:hover {
            background-color: var(--secondary-color);
            transform: translateY(-2px);
        }
        
        .btn:active {
            transform: translateY(0);
        }
        
        .btn-block {
            display: block;
            width: 100%;
        }
        
        .status {
            margin-top: 20px;
            padding: 15px;
            border-radius: 4px;
            display: none;
        }
        
        .status.success {
            background-color: rgba(40, 167, 69, 0.1);
            color: var(--success-color);
            border: 1px solid var(--success-color);
            display: block;
        }
        
        .status.error {
            background-color: rgba(220, 53, 69, 0.1);
            color: var(--danger-color);
            border: 1px solid var(--danger-color);
            display: block;
        }
        
        .status.info {
            background-color: rgba(23, 162, 184, 0.1);
            color: #17a2b8;
            border: 1px solid #17a2b8;
            display: block;
        }
        
        .file-info {
            margin-top: 15px;
            font-size: 14px;
            color: #666;
        }
        
        .features {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 20px;
            margin-top: 30px;
        }
        
        .feature {
            background-color: white;
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
        }
        
        .feature-icon {
            font-size: 2rem;
            color: var(--primary-color);
            margin-bottom: 15px;
        }
        
        .feature-title {
            font-size: 1.2rem;
            margin-bottom: 10px;
            color: var(--secondary-color);
        }
        
        @media (max-width: 768px) {
            .container {
                padding: 15px;
            }
           
            .card {
                padding: 20px;
            }
            
            .features {
                grid-template-columns: 1fr;
            }
        }
        
        /* Loading spinner */
        .spinner {
            display: none;
            width: 40px;
            height: 40px;
            margin: 20px auto;
            border: 4px solid rgba(0, 0, 0, 0.1);
            border-radius: 50%;
            border-top-color: var(--primary-color);
            animation: spin 1s ease-in-out infinite;
        }
        
        @keyframes spin {
            to { transform: rotate(360deg); }
        }