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HTML 

              
                <h1>Matching element heights</h1>
<p>Easily match up heights across a set of non-linear elements. Allows for multiple sets, with each set having a different height defined by an inline <code>min-height</code>.</p>
<p>For use where Flexbox is too cumbersome, or cannot be retro fitted.<br> Only applied above 460px (user defined) browser width in this example.</p>
<p>Note it's only the "yada yada &hellip;" container which is affected.</p>

<div class=container>
  <section class=txt_sctn>
    <a class=txt_lnk href="">
      <span class=img-1></span>
      <span class=txt_container>
        <em class=txt_title>Stuff title</em>
        <span class=txt_content data-matchHeights=A>yada yada yada</span>
        <span class=txt_cta><span class=cta>Get it</span></span>
      </span>
    </a>
  </section>
  <section class=txt_sctn>
    <a class=txt_lnk href="">
      <span class=img-2></span>
      <span class=txt_container>
        <em class=txt_title>Stuff title</em>
        <span class=txt_content data-matchHeights=A>yada yada yada yada yada yada yada yada yada yada yada yada</span>
        <span class=txt_cta><span class=cta>Get it now</span></span>
      </span>
    </a>
  </section>
  <section class=txt_sctn>
    <a class=txt_lnk href="">
      <span class=img-3></span>
      <span class=txt_container>
        <em class=txt_title>Stuff title</em>
        <span class=txt_content data-matchHeights=A>yada yada yada</span>
        <span class=txt_cta><span class=cta>Now get it</span></span>
      </span>
    </a>
  </section>
  <section class=txt_sctn>
    <a class=txt_lnk href="">
      <span class=img-4></span>
      <span class=txt_container>
        <em class=txt_title>Stuff title</em>
        <span class=txt_content data-matchHeights=A>yada yada yada yada yada yada</span>
        <span class=txt_cta><span class=cta>It now get</span></span>
      </span>
    </a>
  </section>
</div>

<h2>How?</h2>
<p>Add data attribute to the elements you wish to equalise and give it a value: <code>data-matchHeights="A"</code>.<br>Ensure the elements each have <code>display: block;</code> and <code>box-sizing: border-box</code>.<br>Then run the script.</p>
<p>All elements with the same data attribute value have the same min-height applied.<br> The min-height is equal to the tallest elements height and is recalculated when the browser width changes.</p>
<p>Proof the "equalised height" blocks do not have to be at all linear: <span class="txt_content solo" data-matchHeights=A>yada yada yada yada yada yada</span></p>
<p>Real life example: <a target=_blank title="[new window]" href="http://www.tesco.com/christmas/">Tesco Christmas 2016</a></p>

<p>Github repo: <a target=_blank title="[new window]" href="https://github.com/2kool2/matching-element-heights">Matching-element-heights</a></p>


<p class=smaller><a target=_blank title="[new window]" href="https://codepen.io/2kool2/pens/public/?grid_type=list#">Pens by Mike Foskett</a> &mdash; <a target=_blank title="[new window]" href="https://websemantics.uk/">webSemantics</a></p>
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CSS 

              
                body {max-width:100%}
.container {
  display: flex;
}
.txt_sctn {
  width: calc(25% - 12px);
  margin-right: 16px;
  float: left;
  background-color: #000;
}
.txt_sctn:last-child {
  margin-right: 0;
}
.txt_lnk {
  display:block;
  border-bottom: 0 solid;
}

[class^="img"] {
  width: 100%;
  display: block;
  background-size: contain;
  background-repeat: no-repeat;
  padding-bottom: 65.45%;
}
.img-1 {
  background-image: url(https://websemantics.uk/portfolio/christmas.2016/i/moments/s5.jpg);
}
.img-2 {
  background-image: url(https://websemantics.uk/portfolio/christmas.2016/i/moments/s6.jpg);
}
.img-3 {
  background-image: url(https://websemantics.uk/portfolio/christmas.2016/i/moments/s7.jpg);
}
.img-4 {
  background-image: url(https://websemantics.uk/portfolio/christmas.2016/i/moments/s8.jpg);
}
.txt_container {
  display: block;
  text-align: center;
  margin-top: .5rem;
}
.txt_title {
  display:block;
}
.txt_content {
  display:block;
  padding: .5rem;
  background-color: rgba(0,0,0,.25);
}
.txt_cta {
  display:block;
  padding: .5rem .25rem;
}
.cta {
  border: 1px solid #999;
  padding:.25rem .5rem;
}

.solo {
  width:25%;
  background-color: rgba(0,0,0,.5);
  padding:.5rem
    
}
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JS 

              
                // Matching non-linear element heights - v1.0 - 18/12/2016 - M.J.Foskett - https://websemantics.uk/
var matchHeights = function () {

  "use strict";

  var dataAttr = "data-matchHeights";
  var minViewportWidth = 460;

  function _getHeightSetsArray(dataAttr) {
    // Return an array containing the different values of data-data-heightmatch
    var value;
    var arr = [];
    var sets = document.querySelectorAll("[" + dataAttr + "]");
    var i = sets.length;
    while (i--) {
      value = sets[i].getAttribute(dataAttr);
      if (arr.indexOf(value) === -1) {
        arr.push(value);
      }
    }
    return arr;
  }

  function _resetMinHeights(set) {
    // reset min-heights by removing the inline style.
    var i = set.length;
    while (i--) {
      set[i].removeAttribute("style");
    }
  }

  function _getMaxSetHeight(set) {
    // return the height of the tallest element in set
    var maxHeight = 0;
    var currentHeight;
    var i = set.length;
    while (i--) {
      currentHeight = set[i].clientHeight;
      if (currentHeight > maxHeight) {
        maxHeight = currentHeight;
      }
    }
    return maxHeight;
  }

  function _setMinHeight(set, matchedHeight) {
    var i = set.length;

    while (i--) {
      set[i].style.minHeight = matchedHeight + "px";
    }
  }

  function init() {

    var sets = _getHeightSetsArray(dataAttr);
    var i = sets.length;
    var set;

    while (i--) {

      set = document.querySelectorAll("[" + dataAttr + "=\"" + sets[i] + "\"]");

      _resetMinHeights(set);

      // Only above minimum screen width
      if (document.body.clientWidth >= minViewportWidth) {

        _setMinHeight(set, _getMaxSetHeight(set));

      }
    }
  }

  init();

};


// https://john-dugan.com/javascript-debounce/
// https://codepen.io/johndugan/pen/BNwBWL?editors=001
var debounce=function(e,t,n){var a;return function(){var r=this,i=arguments,o=function(){a=null,n||e.apply(r,i)},s=n&&!a;clearTimeout(a),a=setTimeout(o,t||200),s&&e.apply(r,i)}};


window.addEventListener("load", matchHeights, false);
window.addEventListener("resize", debounce(matchHeights, 100, false), false);
!
999px

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