.css

Opera User plz jump in and help .. Weird problem in opera...when i use theme made by ico/amvita .css file...digit pages act weird...sometype reply get posted sometime not..sometime post get edited sometime not...sometime signature changes sometime not...but when i dont use these .css file...

is it safe to use themes for forums such as this one. i dowloaded a .css file from the tutorial of this forum... is it safe to use it?

hey wat does n e file with ".css" extension mean? cud u plz provide me details abt .css file? thanx