Margin three
Margin right three
Margin bottom three
Margin horizontal three
Margin vertical three
<div class="m3">Margin three</div>
<div class="mr3">Margin right three</div>
<div class="mb3">Margin bottom three</div>
<div class="mh3">Margin horizontal three</div>
<div class="mv3">Margin vertical three</div>spacing.css, line 132