Studio page stacks paper on a red grid

On a phone the cream letter paper sits directly on the red grid background with the ENHANCE / LOG IN TO SAVE buttons crammed above it; the paper's left and right margins are about 4 px, so the letter looks pasted on.

Give the paper a 12 px gutter and a soft shadow on a black desk surface, put the action buttons in a sticky bottom bar (44 px, safe-area padded) and the LETTER/ENVELOPE toggle as a segmented control.