Whilst Webflow is being upgraded, it would be a good interim to support the use of SASS within the CSS custom code area. The SASS can just be compiled into the page on publishing/exporting the code.
It would definitely tidy up the custom code and make it more manageable to style children elements based on their parent class etc.
I know this can be achieved with CSS alone, but it is far less manageable! Global swatches could be referenced within the SASS as an added bonus!