@page :first {
  margin: 2in    /* Top margin on first page 10cm */
}
@page :left {
  margin-left: 4cm;
  margin-right: 3cm;
}
@page :right {
  margin-left: 3cm;
  margin-right: 4cm;
}
This should do nothing, we don't support :first or :right or :left