span.xx-small {
 font-size:10px !important; 
}
span.x-small {
 font-size:10px !important; 
}

span.small {
 font-size:12px !important; 
}

span.medium {
  font-size:14px !important;
}

span.large {
  font-size:18px !important;
}

span.x-large {
  font-size:24px !important;
}
span.xx-large {
  font-size:36px !important;
}