React Add Days to Date

<!DOCTYPE html>
<html>

<body>
    <div id="app"></div>
    <script type="text/babel">
        const { useState } = React;

function App() {
            const [date, setDate] = useState(new Date());
            const addDays = (days) => {
                const newDate = new Date(date.getTime());
                newDate.setDate(date.getDate() + days);
                setDate(newDate);
            };

return (
                <div className='container'>
                    <h1>React Js Add days to date</h1>
                    <h3>Date: {date.toDateString()}</h3>
                    <button onClick={() => addDays(7)}>Add 7 days</button>
                    <button onClick={() => addDays(30)}>Add 30 days</button>
                </div>
            );
        }

ReactDOM.render(<App />, document.getElementById("app"));
    </script>
    <style>
        * {
            box-sizing: border-box;
        }

.container {
            margin: 0 auto;
            width: 600px;
            text-align: center;
            box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.12), 0 2px 4px 0 rgba(0, 0, 0, 0.24);
            padding: 20px;
        }

h3 {
            font-size: 20px;
            margin-bottom: 10px;
            color: #333;
        }

button {
            display: inline-block;
            padding: 10px 20px;
            font-size: 16px;
            color: #fff;
            background-color: #4CAF50;
            border: none;
            border-radius: 5px;
            cursor: pointer;
            transition: background-color 0.3s ease;
        }

button:hover {
            background-color: #45a049;
        }
    </style>
</body>

</html>