Parse browser supports

@import 'base.sass/+';

$browser-supports: parse-rules(
  'last 5 Chrome versions'
  'last 5 Firefox versions'
  'last 5 Safari versions'
  'IE >= 8'
  'Opera >= 15'
  'iOS >= 5'
  'Android >= 4.2'
);

$colon: unquote(if(support-browser(ie 8), ':', '::'));

.clearfix {
  &#{$colon}before,
  &#{$colon}after {
    content: '\20';
    display: table;
  }

  &#{$colon}after {
    clear: both;
  }

  @if support-browser(ie 7) {
    *zoom: 1;
  }
}