React Js Fullscreen Api

<!DOCTYPE html>
<html>

<body>
    <div id="app"></div>
    <script type="text/babel">
        const { useState, useEffect } = React
        function App() {
            const [isFullscreen, setIsFullscreen] = useState(false);

const toggleFullscreen = () => {
                setIsFullscreen(!isFullscreen);
            };

return (
                <div className='container'>
                    <h3>React Js Toggle Fullscreen</h3>
                    <div className={isFullscreen ? 'fullscreen' : ''}>
                        <button onClick={toggleFullscreen}>Toggle Fullscreen</button>
                    </div>
                </div>

);
        };
        ReactDOM.render(<App />, document.getElementById("app"));
    </script>
    <style>
        .fullscreen {
            background-color: rgba(0, 0, 0, 0.5);
            /* Change to your desired background color */
            position: fixed;
            top: 0;
            left: 0;
            width: 100vw;
            height: 100vh;
        }

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

h3 {
            font-size: 24px;
            margin-bottom: 20px;
        }

p {
            font-size: 18px;
            margin-bottom: 10px;
        }

button {
            padding: 10px 20px;
            font-size: 16px;
            background-color: #4caf50;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
        }

button:hover {
            background-color: #45a049;
        }

button:focus {
            outline: none;
        }

button:active {
            background-color: #3e8e41;
        }
    </style>

</body>

</html>