body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 20px;
            background: #f0f0f0;
        }
        .container {
            max-width: 1200px;
            margin: 0 auto;
            background: white;
            padding: 20px;
            border-radius: 10px;
            box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        }
        .controls {
            margin-bottom: 20px;
        }
        .controls input, .controls textarea {
            width: 100%;
            padding: 10px;
            margin: 5px 0;
            border: 1px solid #ddd;
            border-radius: 5px;
            font-size: 14px;
        }
        .signature-upload {
            display: flex;
            gap: 20px;
            margin: 10px 0;
        }
        .signature-box {
            flex: 1;
        }
        .signature-box input[type="file"] {
            padding: 5px;
        }
        .signature-preview {
            width: 120px;
            height: 40px;
            border: 1px dashed #ccc;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-top: 5px;
            background: #f9f9f9;
        }
        .signature-preview img {
            max-width: 100%;
            max-height: 100%;
        }
        .controls textarea {
            height: 60px;
            resize: vertical;
        }
        .controls button {
            background: #4CAF50;
            color: white;
            padding: 10px 20px;
            border: none;
            border-radius: 5px;
            cursor: pointer;
            font-size: 16px;
        }
        .controls button:hover {
            background: #45a049;
        }
        #certificateCanvas {
            border: 2px solid #ddd;
            border-radius: 5px;
            max-width: 100%;
            height: auto;
        }
        .download-btn {
            background: #008CBA;
            margin-left: 10px;
        }
        .download-btn:hover {
            background: #007B9A;
        }