soapbox/app/styles/components/icon.scss

.svg-icon {
  width: 16px;
  height: 16px;
  display: flex;
  align-items: center;
  justify-content: center;

  > svg {
    max-width: 100%;
    max-height: 100%;
  }
}

.icon-button > div {
  display: flex;
  align-items: center;
  justify-content: center;
}