Panel A (proposed): below 375px the gaps between the bar's controls drop from 10px to 4px, so navigation, the Beta lockup, Search, Ask Holoh, Update and the account menu fit in 320px. Tap targets keep their current sizes: the icon buttons stay 44px and the account menu stays 32px. 375px and up is unchanged.
A · tighter gaps below 375px
320px · light · update ready320px · light · no update320px · dark · update ready320px · dark · no update
375px · light · update ready375px · light · no update375px · dark · update ready375px · dark · no update
1280px · light · update ready · shown at 75%1280px · light · no update · shown at 75%1280px · dark · update ready · shown at 75%1280px · dark · no update · shown at 75%