At-rules are CSS statements that instruct CSS how to behave. They begin with an at sign, @ (U+0040 COMMERCIAL AT), followed by an identifier, and include everything up to the next semicolon, ; (U+003B SEMICOLON), or the next CSS block, whichever comes first....(plus @swash , @ornaments , @annotation , @stylistic , @styleset...Specifies aspects of a page to be printed, such as its dimensions, orientation...