JSFiddle - React, Tailwind, and code Playground

HTML

Default (Outline only on keyboard nav):<br>
<input type="radio" name="test">
<input type="radio" name="test">
<input type="radio" name="test">
<br><br>
:focus (Outline on mouseclick)<br>
<input type="radio" name="test2" class="custom-focus">
<input type="radio" name="test2" class="custom-focus">
<input type="radio" name="test2" class="custom-focus">

CSS

.custom-focus:focus {
    outline: 1px solid black;
}