Numeronym definition obscures nav

Created by: aardrian

Summary

On short viewports the box that defines the numeronym obscures the navigation, covering it completely in some cases.

Found when browser in landscape mode in Firefox Preview on Android, confirmed in a short ChromiEdge window.

Expected result

Navigation would never be obscured.

Actual result

Additional Information

In a very quick test to confirm the issue I found that removing the following fixed it (this is not a recommended fix, just a quick test):

.l-hero {
    height: 75vh;
}