React Js Otp Input

<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.2/umd/react.production.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.2/umd/react-dom.production.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.26.0/babel.min.js"></script>
</head>
<body>
    <div id="app"></div>
    <script type="text/babel">
        const { useState, useRef } = React;

function App() {
            const [otpValues, setOtpValues] = useState(['', '', '', '']);
            const otpFieldsRef = useRef([]);

return (
                <div className='container'>
                    <h3>React Js OTP Input Example</h3>
                    <div className="otp-container">
                        {otpValues.map((value, index) => (
                            <input
                                key={index}
                                type="text"
                                maxLength="1"
                                className="otp-input"
                                value={value}
                                onChange={(e) => handleInput(index, e.target.value)}
                                onKeyDown={(e) => {
                                    if (e.key === 'Backspace') {
                                        handleBackspace(index);
                                    }
                                }}
                                ref={(ref) => {
                                    otpFieldsRef.current[index] = ref;
                                }}
                            />
                        ))}
                    </div>
                </div>
            );
        }

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

body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
        }

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

.otp-container {
            display: flex;
        }

.otp-input {
            width: 40px;
            height: 40px;
            margin: 0 5px;
            border: 2px solid #ccc;
            border-radius: 5px;
            font-size: 24px;
            text-align: center;
            outline: none;
        }

.otp-input:focus {
            border-color: #007bff;
        }

/* Optional: To add more styling for completed inputs */
        .otp-input.completed {
            border-color: #28a745;
        }
    </style>
</body>

</html>