Steps to reproduce:
0 (not sure if relevant): add include-and-override=portal-developer.properties to portal-ext.properties
1: go to public pages -> Configure -> Insert custom CSS that is loaded after the theme.
2: add this CSS:
3. render the page
Expected result: page background has changed
Actual result: CSS is not applied. In the generated HTML markup there is
note the > after the "text/css"