Using media breakpoints in Bootstrap 4-alpha : <p>In Bootstrap 3 I use this:</p>

<pre><code>.something {
    padding: 5px;
    @media screen and (min-width: $screen-sm-min) { 
        padding: 20px;
    }
    @media screen and (min-width: $screen-md-min) { 
        padding: 40px;
    }
}
</code></pre>

<p>How can I do the same thing in Boostrap 4-alpha? I can't find an example in their docs. 
This is in  variables.scss</p>

<pre><code>$grid-breakpoints: (
  xs: 0,
  sm: 576px,
  md: 768px,
  lg: 992px,
  xl: 1200px
) !default;
@include _assert-ascending($grid-breakpoints, "$grid-breakpoints");
@include _assert-starts-at-zero($grid-breakpoints);
</code></pre>
