Fix css for non-posts
Fix css for non-posts

This is work done to get themes play well with Hugo theme preview.

This should maybe be done differently, maybe rename the post css class, but the current styling for non-posts breaks layout.

GrandesDados/hugo-theme-casper,wicast/casper,gotokatsuya/hugo-theme-casper,vjeantet/hugo-theme-casper,LFirestorm/hugo-theme-casper,daustin/hugo-theme-casperilla,jrdjz/hugo-theme-casper,pdan/caspian,GrandesDados/hugo-theme-casper,jrdjz/hugo-theme-casper,vjeantet/hugo-theme-casper,prmtl/hugo-theme-casper,prmtl/hugo-theme-casper,caffeineflo/hugo-theme-casper,daustin/hugo-theme-casperilla,pdan/caspian,wicast/casper,caffeineflo/hugo-theme-casper,gotokatsuya/hugo-theme-casper,LFirestorm/hugo-theme-casper