Datepicker in sidebar does not overlay main area

[CTPassion]

ALL software version info

python 3.11 panel 1.2.3

Description of expected behavior and the observed behavior

Expected: The datepicker pop up overlays the main area when it is placed in the sidebar

Observed: The datepicker exists solely in the sidebar and cannot be seen outside the bounds. Requires the sidebar to be made larger than needed.

Complete, minimal, self-contained example code that reproduces the issue

start_date = pn.widgets.DatePicker(name='Start Date')
end_date = pn.widgets.DatePicker(name='End Date')

template = pn.template.FastListTemplate(
    title="A Simple Layout Dashboard",
    sidebar=[start_date, end_date],
    sidebar_width=200,
)

Screenshots or screencasts of the bug in action

[MarcSkovMadsen]

+1. Hit by this too.

[hoxbro]

It seems to be because of https://github.com/holoviz/panel/blob/88c453b4a4d40de2654135c84c3ed44a96325b98/panel/template/fast/fast.css#L148-L148

Which adds a hidden area in the sidebar:

https://github.com/holoviz/panel/assets/19758978/304ee3a7-3c18-4b9d-aba9-8c85b989c9d7