Wrote a simple 3-equal-column responsive layout. codepen.io/TroyThib/pen/GpfKt

I was working on a much larger project for work that had multiple modules with varying amounts of content. The modules just didn't look very good with their uneven heights, so I wrote a small jQuery script to loop through the DIVs and get the height of the tallest DIV, then make all the DIVs that height. It worked pretty good, and then added a call to the function on resize

The boxes also needed to stack for mobile, which just required changing the float to "none" in the media query. 

  $(document).ready(function() {

    function set_height()

      {

  $('.col').height('inherit'); // reset the height

  var max_h = 0; // variable to hold the max height

  $('.col').each(function(i, obj) { // loop through column DIVs

var h = $(obj).height(); // get the height of the col

    if(h >= max_h) 

{max_h = h;}  

    });

  $('.col').height(max_h);

}

    set_height();

$(window).resize(function(){

 set_height();

});

  });