CSS not working with Bootstrap

[a-a-GiTHuB-a-a]

I have installed everything to allow a button to turn green with the btn-success class, including a link tag for the stylesheet:

<link rel = "stylesheet" href = "https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css">

However, it ruins the CSS that I had inserted:

body {
    color: rgb(255, 0, 0);
    background-color: rgba(255, 0, 0, .5);
}

How do I fix this without removing the green button functionality?

[chinchang]

You mean your button isn't green anymore, even after putting btn-success?

[a-a-GiTHuB-a-a]

No, my background and text colors aren't working.

[Abhishek16-web]

Is it updated or not ?