surquizu,
things are a little confusing. I just made some test. Take for instance this code.
Code:
newpart=* { font-family: Inklings; font-size: 38px; line-height: 42px; } \n
newpart=div.descriptionFont { font-family: Avenir; }\n
newpart=ol {margin-left: 8px} \n
newpart=ol p { font-size: 38px; font-weight:normal; }
newpart=b { font-weight: bold; }\n
newpart=i { font-style: italic; }\n
newpart=b * { font-weight: bold; }\n
newpart=i * { font-style: italic; }
//newpart=::selection { background: #FFFFFF !important; }
First time after restarting the reader, the font-family had no effect on the dictionary view at all. After opening the font menu, there was a small effect (image 1). If after starting nickel one opens the font menu, and only then uses the dictionary the effect s complete (image 2).
I did not see any effect of div.descriptionFont. Maybe this works only for some dictionaries, or Kobo plans to add new tags in future. So it might be better to remove this part again and re-activate ::selection.