Animating Border

Transitioning border for a hover state. Simple, right? You might be unpleasantly surprised.
The Challenge
The challenge is simple: building a button with an expanding border on hover.
This article will focus on genuine CSS tricks that would be easy to drop into any project without having to touch the DOM or use JavaScript. The methods covered here will follow these rules

Single element (no helper divs, but psuedo-elements are allowed)
CSS only (no JavaScript)
Works for any size (not

Animating Border is a post from CSS-Tricks

Link: https://css-tricks.com/animating-border/