fixup css/matchmedia square orientation + subpixels
So, after #30543 (closed) and #43184 (closed) (i.e bugzillas 1607032, 1918202, 1922204) being a good little researcher/tester, I used my laptop and actually tested landscape-portrait-square inner window sizes in each of the four display modes, and I found something interesting - two things actually
So first, my laptop is 3840 x 2160 native res with system scaling at 175% - which means I leak subpixels. I will comment more below
pic - can you spot the two issues?
