:root {
            --primary-color: #3498db;
            --primary-hover: #2980b9;
            --success-color: #2ecc71;
            --success-hover: #27ae60;
            --text-color: #333;
            --light-text: #7f8c8d;
            --background: #f5f5f5;
            --white: #fff;
            --border-color: #ddd;
        }
        
        body {
            font-family: 'Arial', sans-serif;
            line-height: 1.6;
            background-color: var(--background);
            color: var(--text-color);
        }
        
        .container {
            max-width: 800px;
            margin: 20px auto;
            background-color: var(--white);
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        }
        
        h1 {
            color: #2c3e50;
            text-align: center;
            margin-bottom: 20px;
            font-size: 1.5rem;
        }
        
        .upload-area {
            border: 2px dashed var(--primary-color);
            border-radius: 5px;
            padding: 20px;
            text-align: center;
            margin-bottom: 15px;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .upload-area:hover {
            background-color: #f0f8ff;
            border-color: var(--primary-hover);
        }
        
        .upload-area p {
            margin: 0;
            color: var(--light-text);
        }
        
        #fileInput {
            display: none;
        }
        
        .controls {
            margin-bottom: 15px;
        }
        
        .control-group {
            margin-bottom: 10px;
        }
        
        label {
            display: block;
            margin-bottom: 5px;
            font-weight: bold;
        }
        
        input[type="range"] {
            width: 100%;
        }
        
        .preview {
            display: flex;
            flex-direction: column;
            margin-top: 20px;
        }
        
        .preview-item {
            width: 100%;
            text-align: center;
            margin-bottom: 15px;
        }
        
        .preview-item img {
            max-width: 100%;
            height: auto;
            border: 1px solid var(--border-color);
            border-radius: 4px;
            padding: 5px;
            background-color: var(--white);
        }
        
        .preview-item p {
            margin-top: 8px;
            font-weight: bold;
        }
        
        button {
            background-color: var(--primary-color);
            color: white;
            border: none;
            padding: 10px 15px;
            border-radius: 4px;
            cursor: pointer;
            font-size: 14px;
            transition: background-color 0.3s;
            width: 100%;
        }
        
        button:hover {
            background-color: var(--primary-hover);
        }
        
        .download-btn {
            background-color: var(--success-color);
            margin-top: 10px;
        }
        
        .download-btn:hover {
            background-color: var(--success-hover);
        }
        
        .file-info {
            margin-top: 10px;
            font-size: 14px;
            color: var(--light-text);
        }
        
        .hidden {
            display: none;
        }
        
        /* 响应式设计 - 平板和桌面 */
        @media (min-width: 768px) {
            h1 {
                font-size: 2rem;
                margin-bottom: 30px;
            }
            
            .preview {
                flex-direction: row;
                justify-content: space-between;
            }
            
            .preview-item {
                width: 48%;
                margin-bottom: 0;
            }
            
            button {
                width: auto;
                padding: 10px 20px;
            }
            
            .upload-area {
                padding: 30px;
            }
            
            .container {
                padding: 30px;
            }
        }