For example, you can make this "Settings" panel:



Nice and tidy like this:



However it's never worth your time, because it doesn't remember these settings. Next time you need it, it will revert to the ugly default appearance again.

(I bet UI designers in SideFX all use 40" monitors. Otherwise there is no way they can tolerant wasting so much screen space.)

How did you hide it?
Sometimes houdini isn't obvious where you save the defaults tho

Right click then uncheck lock position.

(Yes, to make the background transparent, of course the most obvious way is to uncheck lock position... that's what 40" monitors do to your brain)

But it will revert as soon as you leave the animate state so it's pointless.

This is on the TODO list. If you'd like to keep track, please log an RFE if you haven't already.