Removing this:

  @layer base {
    :root, #nd-docs-layout {
      --fd-layout-offset: max(calc(50vw - var(--fd-layout-width)/2),0px);
    }
  }

EDIT: Oh, or making the window less than around 3000 px wide does also fix it, and resizing you can see what is happening there …

Sorry about that, we've fixed it!