Touchkit table font

Is anybody out there who is able to answer the question : How can I change the font size in a specific table in a Touchkit touchkit appliaction ?
As far as I know the Touchkit is using the built-in touchkit theme. How can I amend it like in the normal vaadin desktop ?
Let us say in case of a button.
@import "../valo/valo.scss";

@mixin mytheme {
  @include valo;

  // Insert your own theme rules here
  .v-button {
  color: #fff;
  background-color: #4455aa;
  border: 1px solid #4455aa;
  text-shadow:2px 2px 0px #474746;
  height: 50px;
  font-family:Trebuchet MS;
  font-weight: bold;
}

Thanks