The 3 CSS Methods for Adding Element Borders
My Colleagues Were Amazed By Borders, by bitbug
CSS Backgrounds and Borders Module Level 3
bitbug – Medium
Basic CSS: Add Borders Around Your Elements
How to border without styling in CSS - Quora
Learn CSS borders in 4 minutes!
How to Construct an Element Border Without Using CSS's border, by bitbug
Basic CSS (10/44), Add Borders Around Your Elements
CSS: Adding Borders to Elements - iLoveCoding