Stephen, is the non-native dark blue focus ring supposed to be this bold and have square corners?

See the attached screenshot from 87 Nightly on macOS with non-native theming enabled.

The left text field is from https://mdn.github.io/learning-area/html/forms/html-form-structure/payment-form.html.

The right text fields are from shorlander's InVision design: https://mozilla.invisionapp.com/share/5CX2MH6EHFB#/screens/415584863_Form_Widgets

The focus ring on the text field on shorlander's form demo page is also less bold than Nightly's: http://stephenhorlander.com/photon/UI-Controls/form-widgets.html

The issue is that that is an unthemed control, because it has border: 1px solid #999. Since it doesn't provide its own outline we draw the native one, but outline generally paints outside of the border area, so that's why it looks "bolder".

This is invalid (as in, the colors are correct). Chrome seems to paint 1px over the border, which is a bit odd, but we could consider doing if this causes issues in more sites.