I'm not entirely sure about the utility of codepen posts, but I'll give it a stab and see what comes from it.
It takes quite a long time to do each one! I want to make sure I'm getting some real gains from the time I spend, so I'm going to consciously pursue new techniques with each daily challenge.
In my CUB effort I got to grips with making the classes as general as possible, and defining additional classes to modify these - usually to place right and left hand versions - where necessary.
I also needed to make use of
z-index to make sure the layering was right, and I learned that I could define these arbitrarily as negative or postive integers to make things go where they needed.
I could have centered my image better. And I needed to do a bunch of repositioning at the end so features didn't drift off when the browser was resized. I guess it matters which side you use to determine your absolute positioning!