When you have big project with many files and dependencies, usually you should care about good code base and periodic cleaning / refactoring. The same situation I had when decided to refactor SCSS files- structure, naming and variables…

I was surprised when figured out- there aren’t good instruments to find unused SCSS variables.

The ways they appear is usual:

• somebody removed use of variable but forgot to delete declaration
• it was used for declaration of another variable or inside some expression
• someone added it "for future" or decided to use variable later
• etc.

About CSS filters

The CSS filter property provides the way to modify rendering for elements in the browser. You can use it to apply visual effects like blur or shifting colors. There are many ways to use it- from providing Instagram/PhotoShop- like filters to the site themes.

Demo