Improve background-editor background-attachment alignment

[wendevlin]

Proposed change

• Change button-group styling to be more flat
• Improve background settings attachment button group

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

[bramkragten]

I dont think this should be a css variable, but the default.

Compare it to a boolean selector, that is also right aligned. This should behave the same.

[wendevlin]

I dont think this should be a css variable, but the default.

Compare it to a boolean selector, that is also right aligned. This should behave the same.

👍 thanks, I did it now differently after feedback from @marcinbauer85

[bramkragten]

Align the label in the center of the control

Like: