How can I customize the css code of the entire website?

This may seem like an inane question, but can I work on the css code of the website - where it shows all of its CSS?

Everytime I try to insert a single line in the “custom css” box, I manage to mess up the entire layout of the website.

For example if I try to make the header fixed on top of the page for all posts, all I manage is to shift it to the left instead of fixing it.

Can anyone help this newb out? :slight_smile:
Or maybe recommend a good css forum or service?


Hey Rowan, can you share what code you’ve tried so far?