Description

Because the notification bar component has default padding values, the notification container can break out of the viewport at sizes that specify a min-width.

The component should use @include border-box; to take into account the extra padding.

Steps to reproduce

This is much clearer on bedrock where we have the notification is use, but you can see the issue on this URL: https://protocol.mozilla.org/patterns/molecules/notification-bar.html

Resize the browser and notice the notification breaks out of its container at around 520px.

Expected result

The notification should adapt well to any screen size.

Actual result

The notification can be wider than it's container.

Environment

Firefox Nightly