"Add Sass styling to components"

This MR marks me finishing the styles for the listed components in issue #28 (closed), and is not requested to be merged for now. This is because I believe that we need to either merge or rebase with issue #29 (closed) before merging to master as there's some components used in both that is possibly fixed in different ways.

If this gets merged anyway:
Closes #28 (closed)
Closes #29 (closed)