Absolute positioning on top-level element causes it not to render

This works fine:
```html
<html-gl>
  <h1>Hello world</h1>
</html-gl>
```

This causes the h1 element to not render:
```html
<html-gl>
  <h1 style="position:absolute">Hello world</h1>
</html-gl>
```

I wasn't able to determine if the positioning is just really offset to some absolute point and it's rendering off-canvas, or if it's not rendering at all.