React Js Convert Date to Unix Timestamp

<!DOCTYPE html>
<html>

return (
        <div className='container'>
          <h3>React Js Convert Date to Unix Timestamp </h3>
          <input
            type="date"
            value={inputDate}
            onChange={(e) => setInputDate(e.target.value)}
            className="date-input"
          />
          <button onClick={convertToTimestamp} className="timestamp-button">
            Convert to Unix Timestamp
          </button>
          <div className="timestamp-result">
            {unixTimestamp !== null ? (
              <p>Unix Timestamp: {unixTimestamp}</p>
            ) : (
              <p>Invalid Date</p>
            )}
          </div>
        </div>

);
    }
    ReactDOM.render(<App />, document.getElementById("app"));
  </script>

/* Style the input field */
    .date-input {
      padding: 10px;
      margin: 10px;
      border: 2px solid #ccc;
      border-radius: 5px;
      font-size: 16px;
      width: 80%;
    }

/* Style the timestamp button */
    .timestamp-button {
      padding: 10px 20px;
      background-color: #007bff;
      color: #fff;
      border: none;
      border-radius: 5px;
      font-size: 16px;
      cursor: pointer;
      transition: background-color 0.3s;
    }

.timestamp-button:hover {
      background-color: #0056b3;
    }

/* Style the timestamp result container */
    .timestamp-result {
      margin: 20px 0;
    }

/* Style the timestamp result text */
    .timestamp-result p {
      font-size: 18px;
      font-weight: bold;
    }

/* Style the "Invalid Date" message */
    .timestamp-result p:last-child {
      color: #ff0000;
      font-weight: normal;
    }

/* Style the "Unix Timestamp" text */
    .timestamp-result p:first-child {
      color: #4caf50;
    }
  </style>
</body>

</html>