@font-face {
  font-family: 'Open Sans';
  font-style: normal;
  font-weight: 300;
  src: local('Open Sans Light'), local('OpenSans-Light'), url(http://themes.googleusercontent.com/static/fonts/opensans/v8/DXI1ORHCpsQm3Vp6mXoaTaRDOzjiPcYnFooOUGCOsRk.woff) format('woff');
}
@font-face {
  font-family: 'Open Sans';
  font-style: normal;
  font-weight: 400;
  src: local('Open Sans'), local('OpenSans'), url(http://themes.googleusercontent.com/static/fonts/opensans/v8/cJZKeOuBrn4kERxqtaUH3bO3LdcAZYWl9Si6vvxL-qU.woff) format('woff');
}
@font-face {
  font-family: 'Open Sans';
  font-style: normal;
  font-weight: 700;
  src: local('Open Sans Bold'), local('OpenSans-Bold'), url(http://themes.googleusercontent.com/static/fonts/opensans/v8/k3k702ZOKiLJc3WVjuplzKRDOzjiPcYnFooOUGCOsRk.woff) format('woff');
}
@font-face {
  font-family: 'Open Sans';
  font-style: normal;
  font-weight: 300;
  src: local('Open Sans Light'), local('OpenSans-Light'), url(//themes.googleusercontent.com/static/fonts/opensans/v8/DXI1ORHCpsQm3Vp6mXoaTaRDOzjiPcYnFooOUGCOsRk.woff) format('woff');
}
@font-face {
  font-family: 'Open Sans';
  font-style: normal;
  font-weight: 400;
  src: local('Open Sans'), local('OpenSans'), url(//themes.googleusercontent.com/static/fonts/opensans/v8/cJZKeOuBrn4kERxqtaUH3bO3LdcAZYWl9Si6vvxL-qU.woff) format('woff');
}
@font-face {
  font-family: 'Open Sans';
  font-style: normal;
  font-weight: 700;
  src: local('Open Sans Bold'), local('OpenSans-Bold'), url(//themes.googleusercontent.com/static/fonts/opensans/v8/k3k702ZOKiLJc3WVjuplzKRDOzjiPcYnFooOUGCOsRk.woff) format('woff');
}
Switch to protocol relative URLs
Switch to protocol relative URLs

Using protocol relative URLs to avoid IE error messages and keep the
site protocol independent.

http://billpatrianakos.me/blog/2013/04/18/protocol-relative-urls/

http://www.paulirish.com/2010/the-protocol-relative-url/
