fix : fixed the UI bug in AuthUI with night mode enabled

[the-dagger]

Fix #502

Relevant Screenshots

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[the-dagger]

I signed the agreement.

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[samtstern]

@the-dagger thanks for this! Happy to merge, but could you change your target branch to version-1.1.0-dev? That's where we're keeping changes for the next version (which is coming very soon)

[the-dagger]

@samtstern Sure, please review #504 🙂