:root {
            --primary: #2a89e3;
            --secondary: #2a89e3;
            --accent: #2a89e3;
            --light: #f8f9fa;
            --dark: #212529;
            --success: #4bb543;
            --danger: #ff3333;
            --warning: #ffcc00;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Poppins', sans-serif;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
            color: var(--dark);
        }
        
        .container {
            background: white;
            border-radius: 16px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
            width: 100%;
            max-width: 800px;
            padding: 40px;
            position: relative;
            overflow: hidden;
            transition: all 0.3s ease;
        }
        
        .container:hover {
            box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
        }
        
        .container::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 8px;
            background: linear-gradient(90deg, var(--primary), var(--accent));
        }
        
        h1 {
            text-align: center;
            color: var(--primary);
            margin-bottom: 30px;
            font-weight: 600;
            font-size: 2.2rem;
        }
        
        .description {
            text-align: center;
            margin-bottom: 40px;
            color: #666;
            font-size: 1.1rem;
        }
        
        .upload-area {
            border: 2px dashed #ccc;
            border-radius: 12px;
            padding: 40px;
            text-align: center;
            margin-bottom: 30px;
            transition: all 0.3s;
            position: relative;
            background: #f9f9f9;
        }
        
        .upload-area:hover {
            border-color: var(--accent);
            background: #f5f5f5;
        }
        
        .upload-area.active {
            border-color: var(--success);
            background-color: rgba(75, 181, 67, 0.05);
        }
        
        .upload-area i {
            font-size: 48px;
            color: var(--primary);
            margin-bottom: 15px;
        }
        
        .upload-area h3 {
            margin-bottom: 10px;
            color: var(--dark);
        }
        
        .upload-area p {
            color: #777;
            margin-bottom: 20px;
        }
        
        .btn {
            background: var(--primary);
            color: white;
            border: none;
            padding: 12px 30px;
            border-radius: 50px;
            font-size: 1rem;
            font-weight: 500;
            cursor: pointer;
            transition: all 0.3s;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 4px 15px rgba(67, 97, 238, 0.3);
        }
        
        .btn:hover {
            background: var(--secondary);
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(67, 97, 238, 0.4);
        }
        
        .btn:active {
            transform: translateY(0);
        }
        
        .btn i {
            margin-right: 8px;
        }
        
        .progress-container {
            width: 100%;
            margin: 30px 0;
            display: none;
        }
        
        .progress-bar {
            height: 10px;
            background: #e9ecef;
            border-radius: 5px;
            overflow: hidden;
            margin-bottom: 10px;
        }
        
        .progress {
            height: 100%;
            background: linear-gradient(90deg, var(--accent), var(--primary));
            width: 0;
            transition: width 0.3s;
        }
        
        .progress-text {
            text-align: center;
            font-size: 0.9rem;
            color: #666;
        }
        
        .result {
            display: none;
            text-align: center;
            animation: fadeIn 0.5s;
        }
        
        .result.success {
            color: var(--success);
        }
        
        .result.error {
            color: var(--danger);
        }
        
        .download-btn {
            background: var(--success);
            margin-top: 20px;
        }
        
        .download-btn:hover {
            background: #3aa33a;
        }
        
        .features {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            margin-top: 40px;
        }
        
        .feature {
            flex: 0 0 calc(33.333% - 20px);
            text-align: center;
            padding: 20px;
            margin-bottom: 20px;
            background: #f8f9fa;
            border-radius: 10px;
            transition: all 0.3s;
        }
        
        .feature:hover {
            transform: translateY(-5px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
        }
        
        .feature i {
            font-size: 32px;
            color: var(--primary);
            margin-bottom: 15px;
        }
        
        .feature h4 {
            margin-bottom: 10px;
            color: var(--dark);
        }
        
        .feature p {
            color: #666;
            font-size: 0.9rem;
        }
        
        footer {
            text-align: center;
            margin-top: 40px;
            color: #666;
            font-size: 0.9rem;
        }
        
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        @media (max-width: 768px) {
            .container {
                padding: 30px 20px;
            }
            
            .feature {
                flex: 0 0 100%;
            }
        }