update header and theme

[frzyc]

Describe your changes

Issue or discord link

Testing/validation

New(left) vs. Old(right)

Mobile

Checklist before requesting a review (leave this PR as draft if any part of this list is not done.)

• [ ] I have commented my code in hard-to understand areas.
• [ ] I have made corresponding changes to README or wiki.
• [ ] For front-end changes, I have updated the corresponding English translations.
• [ ] I have run yarn run mini-ci locally to validate format and lint.
• [ ] If I have added a new library or app, I have updated the deployment scripts to ignore changes as needed

[github-actions[bot]]

[frontend] [Sun Jun 23 04:25:37 UTC 2024] - Deployed c1320193875ac76bc446d0899ee6459c81a939b6 to https://genshin-optimizer-prs.github.io/pr/2261/frontend (Takes 3-5 minutes after this completes to be available)

[frontend] [Sun Jun 23 04:36:37 UTC 2024] - Deployed 27e0939d6d0e3e402b1b8fd6741f8bd5d37a6ddf to https://genshin-optimizer-prs.github.io/pr/2261/frontend (Takes 3-5 minutes after this completes to be available)

[frontend] [Sun Jun 23 11:39:30 UTC 2024] - Deployed 78e379b3ae1a7eae09341ecc1898fd28134d90be to https://genshin-optimizer-prs.github.io/pr/2261/frontend (Takes 3-5 minutes after this completes to be available)

[frontend] [Sun Jun 23 11:42:34 UTC 2024] - Deployed 9f9677a0ca3299500922b6840a9805fa47a19547 to https://genshin-optimizer-prs.github.io/pr/2261/frontend (Takes 3-5 minutes after this completes to be available)

[Mon Jun 24 04:32:26 UTC 2024] - Deleted deployment