[Zope] editing content-type text/css?

zopes, I imported my stylesheet that is called with the <link> tag in all my documents. I intend to continue doing this, as AFAIK the browser can download one instance of the css document and use it for all further documents that refer to it. This is opposed to what I see at some Zoped sites, where style is an object that's included as a <STYLE > tag. I'd like to avoid this because it requires that the CSS be downloaded with each page. Anyway, why doesn't zope (v.2.0.0b5) let me edit the text of the CSS file? thanks, ~mindlace