fontFace function
Inserts a @font-face
rule.
fontFace('''
font-family: "Open Sans";
src: url("/fonts/OpenSans-Regular-webfont.woff2") format("woff2"),
url("/fonts/OpenSans-Regular-webfont.woff") format("woff");
''');
Implementation
void fontFace(String markup) {
sheet.add('@font-face {$markup}');
}