Generated by SassMeister.com.

SassMeister-input.scss

// ----
// libsass (v3.2.5)
// ----

@mixin border-radius($radius) {
  -webkit-border-radius: $radius;
     -moz-border-radius: $radius;
      -ms-border-radius: $radius;
          border-radius: $radius;
}
@mixin pseudo-clear(){
  content:'';
  width:0px;
  height:0px;
  clear:both;
  display: block;
}
.box { 
  @include border-radius(10px);
  &::after{
    @include pseudo-clear();
  }
}

SassMeister-output.css

.box {
  -webkit-border-radius: 10px;
  -moz-border-radius: 10px;
  -ms-border-radius: 10px;
  border-radius: 10px;
}

.box::after {
  content: '';
  width: 0px;
  height: 0px;
  clear: both;
  display: block;
}