Starting to use a CSS minifier

I have started using the 'CSSO' CSS minifier It only reduces the size of my game by 2%. I already used shell and Perl scripts to remove comments and remove some spaces. 'CSSO' additionally removes spaces around '{' and '}' and removes semi-colons after the last property in a rule. Sometimes 'CSSO' combines similar rules and combines properties into a 'shorthand' rule. CSS makes up about 20% of my game. (JavaScripts makes up about 65%). This is after my game is minimised. The size of the CSS is halved when minimised. The minified JavaScript is about 15% of the original size. JavaScript variable names can be shortened but CSS property names cannot be easily shortened. I remove some vendor-prefixed properties. 'CSSO' wrongly changes a small stylesheet to nothing. The stylesheet is: #navigationSettings { display: block; } I had to hide some empty CSS rules from 'CSSO' as it removes them. These rules have prope...