React Js Calculate Age by Date of Birth

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <script src="https://unpkg.com/react@17.0.2/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@17.0.2/umd/react-dom.development.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/@babel/standalone@7.14.6/babel.min.js"></script>
  </head>
  <body>
    <div id="app"></div>
    <script type="text/babel" data-type="module">
      const { useState } = React;

const App = () => {
        const [birthDate, setBirthDate] = useState("");
        const [years, setYears] = useState(null);
        const [months, setMonths] = useState(null);
        const [days, setDays] = useState(null);

const calculateAge = (birthDate) => {
          if (!birthDate) return;

const currentDate = new Date();
          if (new Date(birthDate) > currentDate) {
            setBirthDate("");
            setYears(null);
            setMonths(null);
            setDays(null);
            alert("Invalid Date of Birth");
            return;
          }

const diffTime = currentDate - new Date(birthDate);
          const totalDays = Math.floor(diffTime / (1000 * 60 * 60 * 24));
          setYears(Math.floor(totalDays / 365.25));
          setMonths(Math.floor((totalDays % 365.25) / 30.4375));
          setDays(Math.floor((totalDays % 365.25) % 30.4375));
        };

return (
          <div className="container">
            <h3>Reactjs Calculate age from given date</h3>
            <form>
              <label>Enter your birthdate:</label>
              <input
                type="date"
                value={birthDate}
                onChange={(e) => {
                  setBirthDate(e.target.value);
                  calculateAge(e.target.value);
                }}
              />
            </form>
            {birthDate && (
              <p>
                Your age is {years} years, {months} months, and {days} days
              </p>
            )}
          </div>
        );
      };

ReactDOM.render(<App />, document.getElementById("app"));
    </script>
    <style>
      body {
        margin: 0;
      }
      .container {
        max-width: 800px;
        margin: 0 auto;
        padding: 20px;
        font-family: Arial, sans-serif;
        box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
        position: relative;
      }
    </style>
  </body>
</html>