How to revert to panel's old card CSS?

Panel
1

Using master branch of panel’s card is resulting in awkward cards that span multiple rows rather than a single row:

import panel as pn
pn.extension()

sidebar_col = pn.Column(pn.widgets.Select(options=["A", "B"]))
main_col = [pn.Card("test this", header=pn.widgets.Button())]

dashboard = pn.template.MaterialTemplate(
    title='Test', sidebar=sidebar_col, main=main_col,
    sidebar_width=750)
dashboard.servable()

image

expected (v0.11:
image

2

I think might be related to overflow wrap, but not sure how to overwrite it