Checkbox styles are inconsistent

[maddisondesigns]

Describe the bug
There are so many inconsistencies within the Gutenberg UI. In 3.5.0 the toggle switches have been replaced with checkboxes and they've also been styled to make them more noticeable.

The UI should be consistent. If you have checkboxes in one part of the UI, then they should match checkboxes used in another part of the UI, especially when you're talking about the exact same screen.

The checkboxes in the More menu look completely different to the checkboxes in the sidebar.

To Reproduce
Steps to reproduce the behavior:

1. Edit a page and click on the More menu
2. Compare with the checkboxes in the sidebar, in the Document tab

Expected behavior
The UI should be consistent, and it's not. This is just one of many inconsistencies with the current UI.

Desktop (please complete the following information):

• OS: macOS Sierra 10.12.6
• Browser: Firefox Quantum 61.0.1 (64-bit)
• Gutenberg: 3.5.0

[chrisvanpatten]

They use different styles here because the "checkboxes" in the popover menu aren't actually checkbox form inputs.

They're just icons indicating the menu item is selected/active, like checkmarks in menus in the macOS menubar:

Perhaps there's an argument that the popover menu shouldn't use a checkmark symbol/icon, but it definitely shouldn't use the checkbox styles.

[ZebulanStanphill]

See #8588 for the reasoning behind the current look of checkboxes and why they are used in place of toggles in some cases.

[designsimply]

Closing due to the explanations in #8588.

[maddisondesigns]

That seems fair enough. Thanks.