When you have a lot of content to show on a page you might typically break it up into multiple pages and use pagination to navigate between those pages, this is a common practice on archive pages on blogs. In this pure CSS snippet by Brendan Mullins, we have a really awesome Pagination UX.
When you click on a page number the field expands to show the next and previous two entries, the 1st page will only the first three and the last entry and the last page will only show the last three entries and the first page.
If you are having trouble with the pen, try the archived copy on GitHub
See the Pen Pure CSS pagination by Brendan Mullins (@jsnanigans) on CodePen.0