Why does a CSS border look different on Android?

Question

I have a box with a border.

border: 1px solid #000;

I am using the following viewport setup:

Answer 1

"Could you modify your answer to make it working for all devices, regardless the DPI? Would be super useful! – Basj"

i dont know how much this helpfull here i added a custom function to get border size on almost all dpr