Fieldset legend overlapping fields in vertical tab panes

I'm experiencing an issue that is causing <legend> to be rendered above other fields contained within the <fieldset> when the <fieldset> is contained within a vertical tab pane.

The padding defined by the following selector in the CSS for the Material skin:

body.adminimal-skin-material fieldset {
  ...
  padding-top: 42px;
  ...
}

is overridden by the following selector in the CSS for vertical tabs:

div.vertical-tabs .field-group-tab fieldset {
  ...
  padding: 12px;
  ...
}

I have resolved this by adding the following selector to material.css:

body.adminimal-skin-material .vertical-tabs-panes fieldset {
  padding-top: 42px;
}

The following screenshots show the issue and the result of the fix.

Fieldset legend overlapping field:

Fix applied:

#2551295: [Material skin] fieldset and legend glitch may be related, but it's unclear if the <fieldset> was contained within a vertical tab pane in that issue report.