.aspect {
  position: relative;
  width: 100%;
  height: 0;
  padding-bottom: 100%;
  overflow: hidden; }
  .aspect.aspect-16x9 {
    padding-bottom: 56.25%; }
  .aspect.aspect-4x3 {
    padding-bottom: 75%; }
  .aspect .aspect-inner {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0; }