JSFiddle - React, Tailwind, and code Playground

HTML

<pre><div contenteditable="true">
some<BR />text with<BR />linebreaks.<BR />The intended result<BR />is to style the linbreak<BR />right after the sentence.<BR />
   </div>
 </pre>

CSS

br {
    position:relative;
    display: block;
    border: 1px dotted green;
    font-size: 8px;
    line-height: 8px;
    height: 8px;
    background: yellow;  
    color: blue;
    content: "A";
    width: 5px;
}