How to make options page fit in the border-radius

Add-ons
#1

1. problem

the built-in panels has 3.5px border radius as indicated in photon system page

but the options page in the extension I debugged seemed didn’t agree with the border-radius thing.

the options page floated above the panel ground

2. attempts

I’ve tried to set html and body to border-radius: 3.5px as in extension-mac-panel.css file manually, but it didn’t work!!

#2

You may also have to set overflow: hidden to fully hide the corners.

#3

it’s ineffective. still have no idea how to correct the glitch.