flexbox columns and IE

Question

Everything works fine in Chrome and Firefox but guess what, I have a problem in IE! (IE11)

In my responsive layout I want to menu to be horizontal in pc mode and vertical in tablet/mobile mode. It does just that, but in IE the menu items have no height. They all collapse to 0 height if inspected with the developer tool. I can't find why.

Anyone would have an idea?

I made a codepen for it: http://codepen.io/Reblutus/pen/qjacv

Here is the code

<style>
header {  background: cyan;}
nav {  background: bisque;}
.main-a {  background: tomato;}
.main-b {  background: lightblue;}
footer {  background: lightpink;}

.headerContainer nav {
  display: -webkit-box;
  display: -moz-box;
  display: -ms-flexbox;
  display: -webkit-flex;
  display: flex;
  -webkit-flex-flow: column nowrap;
  flex-direction: column;
}

.headerContainer nav > a {
  padding: 5px 10px;
  text-align: center;
  background: #fcd113;
  border: #6eac2c solid 1px;
  border-width: 0 0 1px;
  -webkit-box-flex: 1;
     -moz-box-flex: 1;
  -webkit-flex: 1;
      -ms-flex: 1;
          flex: 1;
}
@media all and (min-width: 600px) {
  .wrapper {
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    -webkit-flex-flow: row nowrap;
    flex-direction: row;
  }
  .wrapper > .headerContainer {
    -webkit-box-flex: 1;
       -moz-box-flex: 1;
    -webkit-flex: 1;
        -ms-flex: 1;
            flex: 1;
  }
  .wrapper > .mainContainer {
    -webkit-box-flex: 2;
       -moz-box-flex: 2;
    -webkit-flex: 2;
        -ms-flex: 2;
            flex: 2;
  }
  .mainContainer {
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    -webkit-flex-flow: row nowrap;
    flex-direction: row;
  }
  .mainContainer .main-a {
    -webkit-box-flex: 2;
       -moz-box-flex: 2;
    -webkit-flex: 2;
        -ms-flex: 2;
            flex: 2;
    -webkit-box-ordinal-group: 2;
       -moz-box-ordinal-group: 2;
    -ms-flex-order: 2;
    -webkit-order: 2;
            order: 2;
  }
  .mainContainer .main-b {
    -webkit-box-flex: 1;
       -moz-box-flex: 1;
    -webkit-flex: 1;
        -ms-flex: 1;
            flex: 1;
    -webkit-box-ordinal-group: 1;
       -moz-box-ordinal-group: 1;
    -ms-flex-order: 1;
    -webkit-order: 1;
            order: 1;
  }
}

@media all and (min-width: 800px) {
  .wrapper {
    display: block;
  }
  .headerContainer {
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    -webkit-flex-flow: row nowrap;
    flex-direction: row;
  }
  .headerContainer header {
    -webkit-box-flex: 1 200px;
       -moz-box-flex: 1 200px;
    -webkit-flex: 1 200px;
        -ms-flex: 1 200px;
            flex: 1 200px;
  }
  .headerContainer nav {
    -webkit-box-flex: 1 100%;
       -moz-box-flex: 1 100%;
    -webkit-flex: 1 100%;
        -ms-flex: 1 100%;
            flex: 1 100%;
    -webkit-flex-flow: row nowrap;
    flex-direction: row;
  }
}
</style>
<div class="wrapper">
    <div class="headerContainer">
        <header>Logo <i class="fa fa-camera-retro"></i>          </header>
    <nav>
            <a href="javascript:;">Home</a>
            <a href="javascript:;">About Us</a>
            <a href="javascript:;">Our Properties</a>
            <a href="javascript:;">Clients & Partners</a>
        </nav>
    </div>
    <div class="mainContainer">


<div class="main main-a">Main content A</div>
<div class="main main-b">Main content B</div>   </div>
</div>
<footer>footer</footer>

Answer 1

I had a very similar issue with IE11.

Apparently the issue is to do with IE's implementation of the flex property.

In IE10 the default value for flex is 0 0 auto rather than 0 1 auto as defined in the latest spec.

Source: http://caniuse.com/#feat=flexbox

Explicitly setting the flex property to 1 0 auto remedied the issue for my case.

So anywhere you have the flex property set, update the values to match this explicit format.

Answer 2

Removing the flex items in .headerContainer nav > a fixes the problem. Tested in IE11 and Chrome.

... though that does break the wider layouts - so you will have to put them back in for >800px media query.