Yes, the CSS inserts override everything. If they don't it may be due to:
- The existing CSS rule is more specific, i.e. widget.classname li than yours, i.e. widget li
-> make yours more specific, too, by adding classes and/or ID's to your selectors where available
- The existing CSS rule uses an ID selector#id { }, whereas yours only has classes selector.class { }
-> add an ID, too, if the element you want to style (or at least one of its parent elements) has an ID
- If nothing helps
-> add !important after each one of your rules: selector {property: value !important; }