[Bug]: NAV interval is not average

[buyfakett]

Version

System:
    OS: macOS 26.0
    CPU: (8) arm64 Apple M1
    Memory: 123.61 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Browsers:
    Safari: 26.0
  npmPackages:
    @rspress/core: ^v2.0.0-beta.31 => 2.0.0-beta.31 
    @rspress/plugin-llms: ^2.0.0-beta.31 => 2.0.0-beta.31 
    @rspress/plugin-shiki: ^1.45.1 => 1.45.1 
    @rspress/plugin-sitemap: 2.0.0-beta.23 => 2.0.0-beta.23 
    @rspress/plugin-twoslash: 2.0.0-beta.30 => 2.0.0-beta.30

Details

如图所示

当nav的最后一个(脚本)为下拉菜单的时候，和右边的切换主题按钮的间隔没有平均

Reproduce link

https://note.tteam.icu/

Reproduce Steps

1、run pnpm i && pnpm dev
2、view in browser

[SoonIter]

should closed by #2533 in V2