[slider] Incorrect CSS position on vertical slider indicator

[EliotSlevin]

Vertical sliders seem to be doing this:

Screen.Recording.2025-02-26.at.00.58.35.mov

Base-ui is adding the following styles inline as you move:

    position: relative;
    bottom: 0px;
    height: 74%; // changes based on thumb position

I think this should instead be position: absolute?

[mj12albert]

@EliotSlevin You're right, vertical sliders were overlooked when this was decided in #981 (comment)

We should make it relative when horizontal and absolute when vertical, in the mean time you can override it with !important in your styles as a workaround

[mj12albert]

Labelling this ready to take if anybody is interested in working on it