body {
            font-family: 'Arial', sans-serif;
            max-width: 800px;
            margin: 0 auto;
            padding: 20px;
            background-color: #f5f5f5;
        }
        .container {
            background: white;
            padding: 30px;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
        h1 {
            color: #333;
            text-align: center;
        }
        .form-group {
            margin-bottom: 20px;
        }
        label {
            display: block;
            margin-bottom: 5px;
            font-weight: bold;
        }
        input {
            width: 100%;
            padding: 10px;
            border: 1px solid #ddd;
            border-radius: 4px;
            box-sizing: border-box;
        }
        button {
            background: #4CAF50;
            color: white;
            border: none;
            padding: 12px 20px;
            border-radius: 4px;
            cursor: pointer;
            font-size: 16px;
            transition: background 0.3s;
        }
        button:hover {
            background: #45a049;
        }
        #result {
            margin-top: 20px;
            padding: 15px;
            border: 1px solid #ddd;
            border-radius: 4px;
            background: #f9f9f9;
            min-height: 100px;
        }
        pre {
            white-space: pre-wrap;
            word-wrap: break-word;
        }