body {
            font-family: Arial, sans-serif;
            background-color: #f4f4f4;
            margin: 0;
            padding: 20px;
        }
        .container {
            max-width: 400px;
            margin: 0 auto;
            background: white;
            padding: 20px;
            border-radius: 5px;
            box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
        }
        h1 {
            text-align: center;
            color: #333;
        }
        form {
            display: flex;
            flex-direction: column;
        }
        label {
            margin: 10px 0 5px;
        }
        input[type="number"], input[type="submit"] {
            padding: 10px;
            margin-bottom: 10px;
            border: 1px solid #ccc;
            border-radius: 5px;
        }
        input[type="submit"] {
            background-color: #28a745;
            color: white;
            border: none;
            cursor: pointer;
        }
        input[type="submit"]:hover {
            background-color: #218838;
        }