$btn-size: 42px;

.btn {
  outline: none;
  display: block;
  background-color: rgba(0, 0, 0, 0.0);
  margin: 0;
  width: $btn-size;
  height: $btn-size;
  line-height: $btn-size;
  font-size: 16px;
  box-sizing: border-box;
  text-align: center;
  transition: all 300ms ease;
  cursor: pointer;

  &:hover {
    background-color: rgba(0, 0, 0, 0.11);
  }

  &:first-child {
    margin-left: 0;
  }

  &:last-child {
    margin-right: 0;
  }
}

.btn.icon {
  font-size: 20px;
  &:before {
    line-height: $btn-size;
  }
}

.btn.active {
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.26);
  background-color: rgba(0, 0, 0, 0.11);
  &:hover {
    background-color: rgba(0, 0, 0, 0.26);
  }
}