JSFiddle - React, Tailwind, and code Playground

HTML

<div class="main">
</div>

CSS

.main {
    -webkit-column-width: 100px;
    -moz-column-width: 100px;
    column-width: 100px;
    max-height: 200px;
}

.main > div {
    overflow-y:auto;
    border-radius: 6px;
}
.opac {
    opacity: 0.5;
}

JavaScript

$(function() {
   for(var i=0; i<29; i++)
    $('.main').append(
        '<div>'+
            '<div class="opac">opacity '+i+'</div>'+
            '<div>no opacity '+i+'</div>'+
        '</div>'
    ); 
});