.vjs-big-play-button {
  /* The font size is what makes the big play button...big. 
     All width/height values use ems, which are a multiple of the font size.
     If the .video-js font-size is 10px, then 3em equals 30px.*/
  font-size: 0.5em;

  /* We're using SCSS vars here because the values are used in multiple places.
     Now that font size is set, the following em values will be a multiple of the
     new font size. If the font-size is 3em (30px), then setting any of
     the following values to 3em would equal 30px. 3 * font-size. */
  $big-play-width: 3em; 
  /* 1.5em = 45px default */
  $big-play-height: 1.5em;

  line-height: $big-play-height;
  height: $big-play-height;
  width: $big-play-width;
  left: 5px;

  /* 0.06666em = 2px default */
  border: 0.06666em solid $primary-foreground-color;
  /* 0.3em = 9px default */
  border-radius: 0.3em;

  @if $center-big-play-button {
    /* Align center */
    left: 50%;
    top: 50%;
    margin-left: -($big-play-width / 2);
    margin-top: -($big-play-height / 2);   
  } @else {
    /* Align top left. 0.5em = 15px default */
    left: 0.5em;
    top: 0.5em;
  }
}