Buttons come in three sizes. You can control the design for each size.

// BUTTON SMALLoutline
.sqs-block-button-element--small {
  font-size: 18px;
  font-weight: 300;
  text-transform: none;
  letter-spacing: 0.03em;
  color: @logo;
  border: 1px solid @logo;
  padding: 12px 18px;
  opacity: 1;
  transition: @transition;
&:hover {
  color: #FFF !important;
  background-color: @logo;
  opacity: @opacity-high;

For medium or large-sized buttons, just change the two occurrences of small to medium or large.,