Maintain aspect ratio in scss (height = width).

_aspect-ratio.scss

@mixin aspectRatio($ratio: '1:1', $width: 100%) {
  width: $width;
  @if($ratio == '1:1') {
    padding-top: 100%; /* 1:1 Aspect Ratio */
  }
  @else if($ratio == '16:9') {
    padding-top: 56.25%; /* 16:9 Aspect Ratio */
  }
  @else if($ratio == '4:3') {
    padding-top: 75%; /* 4:3 Aspect Ratio */
  }
  @else if($ratio == '3:2') {
    padding-top: 66.66%; /* 3:2 Aspect Ratio */
  }
  @else if($ratio == '8:5') {
    padding-top: 62.5%; /* 8:5 Aspect Ratio */
  }
}