width: -moz-calc(100% - 10px);
  width: -webkit-calc(100% - 10px);
  width: -o-calc(100% - 10px);
  width: calc(100% - 10px);

Feel free to comment if you can add help to this page or point out issues and solutions you have found. I do not provide support on this site, if you need help with a problem head over to stack overflow.