BUG: Fix set_sticky background

[ShawnZhong]

• closes BUG: Style.set_sticky() doesn’t work with dark mode #46984 (Replace xxxx with the Github issue number)
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

Inherit the background-color of the sticky elements from its parents (with proper color alternation between rows) instead of hard-coding it to white.

Example:

import pandas as pd
import numpy as np

pd.DataFrame(np.random.randn(16, 100)).style.set_sticky()

Dark	Light

For reference, #42072 introduced the set_sticky feature.

[jreback]

can you add a note for this, 1.5, styler section

[jreback]

cc @attack68

[attack68]

This is the best solution. LGTM

[mroeschke]

LGTM, failure unrelated. Needs approval from @jreback to merge.

[mroeschke]

Thanks @ShawnZhong

[byrdie]

I think this PR introduced a bit of a regression since it makes the background of the sticky row/column transparent, which makes it harder to read once you scroll to right/down.

You can see the behaviour in the current docuemntation
https://pandas.pydata.org/docs/user_guide/style.html#Sticky-Headers

[attack68]

I think regression is too strong a word for this item, but generally I agree. The underlying issue was reopened and remains outstanding.