fix: improved styling in dark-mode

[fmaclen]

• Fixes minor styling glitches with text editor in dark mode.
• Fixes minor styling issues in sessions with syntax highlighting in dark mode.
• Fixes minor styling issues with primary buttons in dark mode.
• Fixes #46

[fmaclen]

:tada: This PR is included in version 0.7.12 :tada:

The release is available on GitHub release

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