One-direction Margins

An interesting take on something I’ve never really considered before: limiting your CSS margin declarations to one horizontal and one vertical direction, like so:

 div {
   margin-left: 1.5em;
   margin-top: 1.5em;
 }

Which is opposed to how I normally write my margins with values on all four sides. The benefits of writing margins this way allow for greater control of vertical rhythm and also remove the worry of collapsible margins, which means one less thing to worry about. Nice trick.