JSFiddle - React, Tailwind, and code Playground

HTML

<span>
  Hover the text here to reveal it 
  [<reveal><div>abc</div></reveal>]
</span>

SCSS

reveal { 
  display: table-cell;
  & > div {
    overflow: hidden; width: 0%;
    transition: width 0.25s; 
  }
  &:hover > div {
    width: 100%;
  }
}
/* just for style purposes */
reveal > div { color: red; }