pseudo-elements disappear in ie10 in combination with flexbox

Question

I've a problem with the IE10 and flexbox. At the moment I use code like the snippet below.

The content of col 2 has got a variable length (with multiple small elements) and it should take the width it needs. I want to have to rows with a line between them. Therefor I added an pseudo-element, put it on the correct position via order with a width of 100%.

Chrome, Firefox, etc. can render this example, but if I run it with IE10, the pseudo-element disappears and the content of the second row moves itself to the first row.

Isn't the IE10 able to render pseudo-elements together with flexbox? Do you know a 'hack' to force this break?

/* Container */
.container {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  width: 200px;
 }

.container:after {
  background-color: #000;
  content: '';
  height: 2px;
  margin: 5px 0;
  order: 3;
  width: 100%;
}
/* Child */
.child {
  width: 100px;
  border: 1px solid red;
  box-sizing: border-box;
  height: 50px;
  line-height: 50px;
  text-align: center;
}
/* Positioning of the childs */
.c1 {
  order: 1
}

.c2 {
  order: 2
}

.c3 {
  order: 4
}

.c4 {
  order: 5
}

<div class="container">
  <div class="child c1">row 1 col 1</div>
  <div class="child c2">row 1 col 2</div>
  <div class="child c3">row 2 col 1</div>
  <div class="child c4">row 2 col 2</div>
</div>

Answer 1

You need to add this styles for .container to work in IE10:

display: -ms-flexbox;
-ms-flex-wrap: wrap;