[css] Using a custom (ttf) font in CSS

You need to use the css-property font-face to declare your font. Have a look at this fancy site: http://www.font-face.com/

Example:

@font-face {
  font-family: MyHelvetica;
  src: local("Helvetica Neue Bold"),
       local("HelveticaNeue-Bold"),
       url(MgOpenModernaBold.ttf);
  font-weight: bold;
}

See also: MDN @font-face