[Dialog] Page is scrolled to top when opening the dialog if html { scroll-behavior: smooth }

[benface]

Bug report

Current behavior

Super weird one, but like the title says! I can reproduce in Chrome and Safari; it works fine in Firefox.

Expected behavior

The page should not be scrolled to the top when the dialog opens.

Reproducible example

https://codesandbox.io/p/sandbox/competent-chandrasekhar-8wcv88

Base UI version

1.0.0-alpha.5

Which browser are you using?

Chrome 132.0.6834.84, Safari 18.2

Which OS are you using?

macOS

Which assistive tech are you using (if applicable)?

None

Additional context

Thank you 🙏

[atomiks]

It seems the scroll lock needs to unset the scroll-behavior style inline.

This fixes it as a workaround:

  html:not([data-base-ui-scroll-locked]) {
    scroll-behavior: smooth;
  }