navbar cannot cover content when visit directly on a built site which url is with hash

[jellyfishgh]

Describe the bug

1. open url with hash (eg: https://vitejs.dev/plugins/#community-plugins ) in browser;
2. navbar is transparent so we can see content behind the navbar;
   

Reproduction

open https://vitejs.dev/plugins/#community-plugins in browser

Expected behavior

navbar can cover content and we can not see content behind the navbar.

System Info

System:
    OS: macOS 13.3.1
    CPU: (8) arm64 Apple M1
    Memory: 255.67 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 18.16.0 - /usr/local/bin/node
    npm: 9.5.1 - /usr/local/bin/npm
  Browsers:
    Safari: 16.4

Additional context

No response

Validations

• Check if you're on the latest VitePress version.
• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.

[zonemeen]

It seems to happen only when there is no sidebar. Similar to the problem of #2442