* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background: #e3e3e4;
            color: #333;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            padding: 20px;
        }
        
        .container {
            width: 100%;
            max-width: 900px;
            background: rgba(255, 255, 255, 0.95);
            border-radius: 20px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
            overflow: hidden;
            margin: 20px 0;
        }
        
        header {
            background: linear-gradient(to right, #6e8efb, #a777e3);
            color: white;
            padding: 25px;
            text-align: center;
        }
        
        h1 {
            font-size: 2.5rem;
            margin-bottom: 10px;
        }
        
        .subtitle {
            font-size: 1.1rem;
            opacity: 0.9;
        }
        
        .main-content {
            padding: 30px;
            display: flex;
            flex-direction: column;
            gap: 25px;
        }
        
        .upload-section {
            text-align: center;
            padding: 30px;
            border: 3px dashed #a777e3;
            border-radius: 15px;
            background: rgba(167, 119, 227, 0.1);
            transition: all 0.3s;
        }
        
        .upload-section:hover {
            background: rgba(167, 119, 227, 0.2);
        }
        
        .upload-icon {
            font-size: 4rem;
            color: #6e8efb;
            margin-bottom: 15px;
        }
        
        .upload-text {
            margin-bottom: 20px;
        }
        
        .btn {
            background: linear-gradient(to right, #6e8efb, #a777e3);
            color: white;
            border: none;
            padding: 12px 25px;
            border-radius: 50px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s;
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }
        
        .btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        }
        
        .btn:active {
            transform: translateY(0);
        }
        
        .btn:disabled {
            background: #cccccc;
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
        }
        
        .btn i {
            font-size: 1.2rem;
        }
        
        #file-input {
            display: none;
        }
        
        .preview-section {
            display: none;
            flex-direction: column;
            gap: 20px;
        }
        
        .video-preview {
            width: 100%;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        }
        
        .video-preview video {
            width: 100%;
            display: block;
        }
        
        .controls {
            display: flex;
            flex-wrap: wrap;
            gap: 15px;
            justify-content: center;
        }
        
        .format-options {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            justify-content: center;
            margin: 10px 0;
        }
        
        .format-btn {
            padding: 8px 20px;
            background: #e0e0e0;
            border: none;
            border-radius: 50px;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .format-btn.active {
            background: #6e8efb;
            color: white;
        }
        
        .progress-section {
            display: none;
            flex-direction: column;
            align-items: center;
            gap: 15px;
            padding: 20px;
            background: #f5f5f5;
            border-radius: 10px;
        }
        
        .progress-bar {
            width: 100%;
            height: 10px;
            background: #e0e0e0;
            border-radius: 5px;
            overflow: hidden;
        }
        
        .progress {
            height: 100%;
            background: linear-gradient(to right, #6e8efb, #a777e3);
            width: 0%;
            transition: width 0.3s;
        }
        
        .result-section {
            display: none;
            flex-direction: column;
            align-items: center;
            gap: 20px;
            padding: 20px;
            background: #f0f5ff;
            border-radius: 10px;
            text-align: center;
        }
        
        .download-btn {
            text-decoration: none;
        }
        
        .audio-player {
            width: 100%;
            margin: 15px 0;
            border-radius: 5px;
            background: #f5f5f5;
        }
        
        footer {
            text-align: center;
            padding: 20px;
            color: #6e8efb;
            font-size: 1rem;
            opacity: 0.8;
        }
        
        .error-message {
            display: none;
            color: #e74c3c;
            background: #ffebee;
            padding: 10px;
            border-radius: 5px;
            margin: 10px 0;
            text-align: center;
        }
        
        @media (max-width: 768px) {
            h1 {
                font-size: 2rem;
            }
            
            .main-content {
                padding: 20px;
            }
            
            .upload-section {
                padding: 20px;
            }
            
            .upload-icon {
                font-size: 3rem;
            }
            
            .btn {
                padding: 10px 20px;
            }
        }
        
        @media (max-width: 480px) {
            h1 {
                font-size: 1.8rem;
            }
            
            .subtitle {
                font-size: 1rem;
            }
            
            .upload-icon {
                font-size: 2.5rem;
            }
            
            .controls {
                flex-direction: column;
                align-items: center;
            }
        }