A system, method and a computer-readable medium for optimizing cascading style sheet (CSS) rules. The system includes a parser, an optimizer and a compiler. The parser is configured to generate a template tree and a CSS tree. The template tree is associated with a template file that includes one or more templates. The CSS tree is associated with a CSS file that includes one or more CSS rules. The optimizer is configured to traverse the template tree and the CSS tree, and identify each node in the template tree that has a reference to a CSS node in the CSS tree. When the reference exists, optimizer retrieves a CSS rule from the CSS node and appends the CSS rule to the node in the template tree. The compiler compiles the appended template tree.