%button {
  position: relative;
}
%button .progress.indeterminate {
  position: absolute;
  top: 50%;
  left: 50%;
  margin-left: -12px;
  margin-top: -12px;
}
%button:disabled .progress + * {
  visibility: hidden;
}
%button:empty {
  padding-right: 0 !important;
  padding-left: 18px !important;
  margin-right: 5px;
}
%button:empty::before {
  left: 1px;
}
%button:not(:empty) {
  display: inline-flex;
  text-align: center;
  justify-content: center;
  align-items: center;
  padding: calc(0.5em - 1px) calc(2.2em - 1px);
  min-width: 100px;
}
%button:not(:last-child) {
  margin-right: 8px;
}
%button-compact {
  padding-top: calc(0.4em - 1px) !important;
  padding-bottom: calc(0.4em - 1px) !important;
}
%internal-button {
  padding: 0.9em 1em;
  text-align: center;
  display: inline-block;
  box-sizing: border-box;
}