JSFiddle - React, Tailwind, and code Playground

HTML

<div class="mytest class1"> test </div>
<div class="mytest class2"> test </div>
<div class="mytest class3"> test </div>
<div class="mytest class4"> test </div>
<div class="mytest test"> test </div>

CSS

.mytest[class*="class"]{
    color: blue;
}