Reddit mentions of CSS Secrets: Better Solutions to Everyday Web Design Problems

Lea Verou's CSS Secrets:
http://www.amazon.com/CSS-Secrets-Lea-Verou/dp/1449372635
it's a seriously great resource even if you think you know CSS.

Recently read a rather wonderful book called 'CSS Secrets' by a CSS wizard by the name of Lea Verou, within the book she talks extensively about creating your own background patterns:

https://www.amazon.com/CSS-Secrets-Solutions-Everyday-Problems/dp/1449372635/ref=sr_1_1?ie=UTF8&qid=1467577766&sr=8-1&keywords=CSS+Secrets

It's well worth a read not just for the background patterns, but a host of other cool CSS stuff.

After discovering this book and having a mooch around the web for similar effects I realised she had a gallery of some of the designs shes made already. Perhaps some of these might fit the bill for you?

http://lea.verou.me/css3patterns/

The bible is very much Lea Verou's CSS Secrets - give that a read!

When you learn JS you learn super basic stuff like variables, loops, and functions, and then everything from that moment on is just learning all the first and 3rd-party APIs - treat CSS the same way. Lots of functionality in CSS is locked behind attribute-pairs, and so that's a good way to approach it.

For example, super basic - you want to change height/width? You need to unlock those properties with display: block; because display: inline; by its nature doesn't support it. Once you've got that you've unlocked margins, padding etc. If you want to move an element about then you need to specify position first, because that's what top, left, bottom, right, and z-index are hidden behind etc etc.

You've been doing this for a decade, and you're coming from a technical background - so all you need to do is approach CSS in a similar way - that is, procedurally! Hit me up if you want a more solid step-by-step on a good learning order.