JSFiddle - React, Tailwind, and code Playground

HTML

<span>space!</span>
<a href="#" onclick="animateToTop(event)">to the top</a>
<span>more space!</span>
<a href="#" onclick="animateToTop(event)">to the top</a>
<span>even more space!</span>
<a href="#" onclick="animateToTop(event)">to the top</a>

CSS

span {
display: block;
margin: 250px 0;
}

JavaScript

function animateToTop(e) {
    e.preventDefault();
    var scrollToTop = window.setInterval(function() {
        var pos = window.pageYOffset;
        if ( pos > 0 ) {
            window.scrollTo( 0, pos - 20 );
        } else {
            window.clearInterval( scrollToTop );
        }
    }, 16);
}