CSS Refactor

The CSS/SCSS of the project has become a bit of a patchwork, with things being added over time. There is a lot of code that isn't needed anymore, duplicate code that could be gotten rid of, and some code used for older browsers that we may not need anymore, and there is a lot of random inline CSS that should be done in CSS/SCSS. We could also do a lot to standardize the colors that we are using across the app and setup a proper color system.

There are a lot of ways to go about this, I would like to see us move to a more modern system using CSS custom properties instead of SASS variable since that would make theming and color switching easier and doesn't require a build step.

This isn't a high priority need because what we have is working for now, but it is worth consideration and discussion.