Don't purposefully put yourself in style sheet hell. Come to the light.
The #1 problem I see for people learning CSS - or working on an existing project is: Bootstrap, Foundation, Material - or any other CSS 'framework.'
They mean well, both the framework creators and the people that choose to use them... but it's probably the most expensive part of the current development sycle. The logic behind these massive sets of CSS rules is solid, but the landscape has changed. The people that know them like the back of their hand, stick with it! If you are making a desktop-only form-filled mvp - use bootstrap, but if you do not know CSS... run. Same goes for BEM and other 'atomic' methodologies.
CSS is the best it has ever been. With preprocessing and flexbox - it's time to rethink why you "don't get why CSS doesn't work." Read this: https://maintainablecss.com/chapters/introduction/ (I only agree with most of this) - and check out stylus. Setup a meeting with me, and I can show you how to write enjoyable markup and Stylus rules to make authoring websites/apps super fun.