This is really frustrating. I mean, styling with CSS is really essential for us to be able to provide WIX to our clients.
I’m currently just trying to set a freaking margin on the Gallery Pro component. This is an awful restriction which means that we need to find another platform for the majority of our clients 
I suspect this restriction is based on that everything about size and position being calculated by javascript due to the absolute positioning-only solution in the Wix platform? Meaning, having custom CSS like a simple style will ruin layout code etc.
I talked with Wix about fully responsive designs (very much wanted!) yesterday and got the news that they announced support for this and it will be released before the end of 2019. Perhaps the new Editor might introduce some CSS support then too! Did anyone else get this news?
Ps. and yes, I’ve voted on every feature vote I can find regarding full responsive designs and css capabilities.