Q:

CSS Grid Layout with full height on IE

I started using CSS Grid Layout by great Rachel Andrews and I cant figure out, how can I stretch wrapper. I am using her first example from book Get Ready for CSS Grid Layout with a little modification - full height.
It works perfect on Chrome, FF, Safari, Opera - but it doesn't fill full height on IE. I am using IE prefixes for grid system (-ms-) and everything works but not full height.

.wrapper {
  display: grid;
  display: -ms-grid;
  grid-template-columns: 12px calc(50vw - 18px) 12px calc(25vw - 18px) 12px calc(25vw - 12px) 12px;
  -ms-grid-columns: 12px calc(50vw - 18px) 12px calc(25vw - 18px) 12px calc(25vw - 12px) 12px;
  grid-template-rows: 12px auto 12px auto 12px;
  -ms-grid-rows: 12px auto 12px auto 12px;
  background-color: #fff;
  color: #444;
  height: 100vh;
}

.box {
  background-color: rgb(120, 70, 123);
  border: 5px solid rgb(88, 55, 112);
  color: #fff;
  border-radius: 5px;
  padding: 20px;
  font: 150%/1.3 Lucida Grande, Lucida Sans Unicode, Lucida Sans, Geneva, Verdana, sans-serif;
}

.a {
  grid-column: 2 / 3;
  grid-row: 2 / 5;
  -ms-grid-column: 2;
  -ms-grid-column-span: 1;
  -ms-grid-row: 2;
  -ms-grid-row-span: 3;
}

.b {
  grid-column: 4 / 7;
  grid-row: 2 / 3;
  -ms-grid-column: 4;
  -ms-grid-column-span: 3;
  -ms-grid-row: 2;
  -ms-grid-row-span: 1;
}

.c {
  grid-column: 4 / 5;
  grid-row: 4 / 5;
  -ms-grid-column: 4;
  -ms-grid-column-span: 1;
  -ms-grid-row: 4;
  -ms-grid-row-span: 1;
}

.d {
  grid-column: 6 / 7;
  grid-row: 4 / 5;
  -ms-grid-column: 6;
  -ms-grid-column-span: 1;
  -ms-grid-row: 4;
  -ms-grid-row-span: 1;
}
<div class="wrapper">
  <div class="box a">A</div>
  <div class="box b">B</div>
  <div class="box c">C</div>
  <div class="box d">D</div>
</div>

Also there is working jsfiddle: https://jsfiddle.net/v7d641jb/
(if you want to check the whole example its here http://legie.kirril.com/www/grid/index.html)

A:

Although the CSS Grid Spec (the older one which is supported by IE) does define an auto value for grid-rows, it obviously isn't working in IE.
The simple solution is to replace auto with 1fr.
Instead of this:
-ms-grid-rows: 12px auto 12px auto 12px;

Try this:
-ms-grid-rows: 12px 1fr 12px 1fr 12px;

revised fiddle

