JSFiddle - React, Tailwind, and code Playground

HTML

<div contenteditable>
<span contenteditable class="focus">I will stay the same when you type inside me!</span>
</div>

<span contenteditable class="focus">I will turn red when you type inside me!</span>

CSS

.focus:focus {
    color: white;
    background: red;
}

div:focus span {
    color: white;
    background: green;
}