Use pixels instead of rem units for focus box-shadow on custom controls so that IE11, Edge, and Win FF screw it up less
$custom-control-checked-indicator-bg: $brand-primary !default;
$custom-control-checked-indicator-box-shadow: none !default;
-$custom-control-focus-indicator-box-shadow: 0 0 0 .075rem $body-bg, 0 0 0 .2rem $brand-primary !default;
+$custom-control-focus-indicator-box-shadow: 0 0 0 1px $body-bg, 0 0 0 3px $brand-primary !default;
$custom-control-active-indicator-color: $white !default;
$custom-control-active-indicator-bg: lighten($brand-primary, 35%) !default;