If no changes are showing then it is possible that you have TWO instances of an ID or class in the stylesheet.

You are making edits to the first one, but the SECOND one (scroll down till you find it) is over-riding what the first one is saying... so you see no changes.

Styles are applied alpha-chronologically (in terms of stylesheet names) and then the declarations are applied sequentially.

Later duplicates of an ID/Class declaration will override earlier declarations.