A floating Commit button lands on mobile
Your phone's log now has a round Commit button parked above the tab bar. Tap it and the composer wakes, or the Write a commit dialog opens if the composer is out of sight.
You're halfway down the log on your phone, thumb tired of reaching for the top. A round Commit button hovers at the bottom right, just above the tab bar. Tap it and the page doesn't jump. You're either typing in the composer already at the top of the log, or looking at the Write a commit dialog.
Credit xHeaven, who gave phones the button the desktop sidebar has had all along, wired to the same action as the c key. The circle is 56 pixels across, 16 pixels in from the right edge and 16 pixels above the bottom nav's measured height, safe area included. Pages that aren't Remotes get 160 pixels of bottom padding, up from 80, so the last commit's buttons scroll clear.
It checks whether the composer at the top of the log is really on screen, not merely present, and puts your cursor in it. Scroll it away and the Write a commit dialog opens instead. Guests are sent to GitHub to sign in. At 768 pixels wide the button vanishes and the sidebar's own Commit button takes over. Remotes never gets one, because the message box owns the bottom there.
One catch. Toasts park at the same height above the nav and run the full width of the screen, so a "pending review" message sits on the button until it fades.