css - css coding that I have never seen

Question

I am studying a free css template called zerofour found at http://html5up.net/zerofour/, and running across a css coding that I have never seen before. In the HTML, some div

Answer 1

Read this spec: http://www.w3.org/International/questions/qa-escapes#cssescapes. The characters following the back slash represent a unicode code point. The space is required if the next character is allowed as part of the hexadecimal values.