How to implement this in pure css without pulling up the sprite?

Question

css

Goodnight. Please tell me how to make the same rounding without using a substrate.
Example - https://jsfiddle.net/jw6mqpsa/
Many thanks in advance to everyone.

Answer 1

You can try something like this
jsfiddle.net

Answer 2

caniuse.com/#search=clip-path
two options to choose from