Why is the svg in this code not 40px high, but 100?

Question

css

Here is the code:
codepen.io/aliencash/pen/LxVopr?editors=1100#0
Of course, I can also force height: 40px for svg; but it's not clear why the svg is not constrained by the parent's forced height, why the viewbox is ignored, and in general WHAT'S HAPPENING?

Answer 1

Found the answer on stack - stackoverflow.com/questions/39260135/why-does-the-...

Answer 2

You've got steel

.key-svg {
  width: 40px;
  height: 40px;
  padding: 0;
  box-sizing: border-box;
  border-radius: 1000px;
}