Q:

Number of columns ok in Chrome but not in IE and Firefox

[Removed link]
There should be 5 columns. Each post has a 20% width, it looks ok in Chrome but in IE and Firefox the last column gets pushed below so there are only 4. Does anybody know why?
.post {
  width: 20%;
  float: left;
  overflow: hidden;
}

<article class="col post">
    stuff inside
</article>
<article class="col post">
    stuff inside
</article>
<article class="col post">
    stuff inside
</article>
....

A:

Found my answer here: https://github.com/desandro/masonry/issues/166 I changed 20% to 19,8%

Looks like Firefox calculates percentage widths a bit different than
  WebKit. An easy fix is to allow a wee bit of wiggle room in your CSS
  layout so that the columns don't add up to 100%.

