Single post in Guide to CSS (Beginner & Intermediate) [In Progress]

I'm really confused on how to make tabs in CSS. I'm making a template for a shop (I'm very new to CSS). I have the about template made by sceptios, so I referenced that for tabs, but I can't figure it out. The "tabs" section in the OP just has the word "text" in it and it hasn't been updated in 2 years. Help..? P.S. If you need the code for my shop that I've made so far, I can PM it to you.