@mixin clearfix {
  &:after {
    clear: both;
    content: "";
    display: block;
  }
}

@mixin clear-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

@mixin font-aa {
  -webkit-font-smoothing: antialiased;
}

@mixin optimizeLegibility {
  text-rendering: optimizeLegibility;
}

@mixin placeholder {
  &::-webkit-input-placeholder { /* Chrome/Opera/Safari */
    @content;
  }

  &::-moz-placeholder { /* Firefox 19+ */
    @content;
  }

  &:-ms-input-placeholder { /* IE 10+ */
    @content;
  }

  &:-moz-placeholder { /* Firefox 18- */
    @content;
  }
}