.#{$n}-collapse-button {
  display: flex;
  position: absolute;
  z-index: 1;
  top: $spacer;
  right: $spacer;
  align-items: center;
  justify-content: center;
  width: $buttonsize;
  height: $buttonsize;
  padding: 0;
  border: 0 none;
  border-radius: 50%;
  background-color: $white;
  box-shadow: $boxshadow;
}