How to make this decorative element?

Question

css

Good day.
Tell me, how best to implement the appearance of a white inner frame, shown in the picture below, when you hover the mouse over a block with text?

Answer 1

An absolute positioned block that has a top, right, and bottom border. The left border is implemented via the :before (with top: 0px) and :after (with bottom: 0px) pseudo-elements.

Answer 2

There are a lot of ways from pleio-elements to background ...
Let it be the most stupid: https://jsfiddle.net/aovpdwvz/2/