body {
font-family: Arial, sans-serif;
}
.container {
width: 50%;
margin: 0 auto;
}
.form-group {
margin-bottom: 10px;
}
.btn {
background-color: #007bff;
color: white;
padding: 5px 10px;
border: none;
cursor: pointer;
}

function convertToMP3() {
var youtubeUrl = document.getElementById(‘youtubeUrl’).value;
// Validate YouTube URL
if (!youtubeUrl.includes(“youtube.com”)) {
document.getElementById(‘result’).innerHTML = “Please enter a valid YouTube URL”;
return;
}
var mp3Url = youtubeUrl.replace(“youtu.be”, “youtube.com”).replace(“watch?v=”, “embed/”) + “&format=mp3”;
document.getElementById(‘result’).innerHTML = “Download MP3“;
}

This is a simple YouTube to MP3 Converter created using HTML, CSS and JavaScript.
The user can enter a YouTube URL in the input field and click the ‘Convert to MP3’ button.
The function convertToMP3() will check if the input is a valid YouTube URL and then generate a direct MP3 link which the user can download by clicking on it.

Feel free to customize this converter further by adding more features or styling elements. Let your creativity guide you and enjoy converting your favorite YouTube videos to MP3 format!