SVG inside a div in CSS grid is adding some extra padding to the bottom, why?

I am trying to display a grid of SVGs using CSS grid. Something simple like this example, which is just divs, no SVGs yet. This works fine.

#wrapper {
  display: grid;
  grid-gap: 2px;
  grid-template-columns: 1fr 1fr 1fr 1fr 1fr;
  width: 650px;
  
  .child {
    background-color: green;
    aspect-ratio: 2/3;
  }
}

<div id="wrapper">
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
</div>

Now if I add an SVG inside one of the divs, it messes up the alignment:

#wrapper {
  display: grid;
  grid-gap: 2px;
  grid-template-columns: 1fr 1fr 1fr 1fr 1fr;
  width: 650px;
  
  .child {
    background-color: green;
    aspect-ratio: 2/3;
  }
}

<div id="wrapper">
  <div class="child"></div>
  <div class="child"><svg viewBox="0 0 400 600" style="background-color: black"><circle r="45" cx="50" cy="50" fill="red" /></svg></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
</div>

Somehow it's adding a little extra padding to the bottom of the "child" div that contains the SVG, but I can't figure out why that's happening or how to prevent it. Any ideas?

Solution

SVG's are considered inline elements, and so they have a height defined by line-height (which might be inherited).

The answer here goes in much more detail: Inline elements and line-height

So the options to fix would be to set your svg elements to display: block;. Or adjust the line-height of these elements based on the size of the SVG (or to line-height: 0, but that has always felt kind of hacky to me).