:root {
            --primary-color: #4CAF50;
            --secondary-color: #2196F3;
        }
        body {
            font-family: 'Microsoft YaHei', sans-serif;
            max-width: 100%;
            background-color: #f5f5f5;
            box-sizing: border-box;
        }
        h1 {
            color: #333;
            text-align: center;
            margin-bottom: 20px;
        }
        .container {
            background-color: white;
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            max-width: 1000px;
            margin: 20px auto;
        }
        .preview-container {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            margin-top: 20px;
            gap: 20px;
        }
        .preview-box {
            flex: 1 1 300px;
            min-width: 300px;
            text-align: center;
        }
        #originalPreview, #watermarkedPreview {
            max-width: 100%;
            max-height: 300px;
            border: 1px solid #ddd;
            margin-top: 10px;
            object-fit: contain;
        }
        .controls {
            margin-top: 20px;
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 15px;
        }
        .control-group {
            margin-bottom: 15px;
        }
        label {
            display: block;
            margin-bottom: 5px;
            font-weight: bold;
        }
        input, select {
            width: 100%;
            padding: 8px;
            border: 1px solid #ddd;
            border-radius: 4px;
            box-sizing: border-box;
        }
        button {
            background-color: var(--secondary-color);
            color: white;
            border: none;
            padding: 10px 15px;
            border-radius: 4px;
            cursor: pointer;
            font-size: 16px;
            transition: background-color 0.3s;
        }
        button:hover {
            background-color: #0b7dda;
        }
        .checkbox-group {
            display: flex;
            align-items: center;
        }
        .checkbox-group input {
            width: auto;
            margin-right: 10px;
        }
        .tiled-controls {
            display: none;
            margin-top: 10px;
            padding: 10px;
            background-color: #f0f0f0;
            border-radius: 4px;
        }
        .color-picker-group {
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .color-picker-group input[type="color"] {
            width: 50px;
            height: 40px;
            padding: 0;
            border: none;
        }
        @media (max-width: 768px) {
            .preview-container {
                flex-direction: column;
            }
            .preview-box {
                width: 100%;
            }
        }