On a phone the floating cards can't sit over the canvas, so the controls move to a FAB-driven surface. The canvas + dieline stays full-screen; tap the button to reveal controls. (Tap the buttons in each phone to try them.)
A single FAB opens a draggable bottom sheet holding the same collapsible cards. Canvas stays behind; swipe down or tap ✕ to dismiss. The standard, most familiar pattern.
FAB ⚙ bottom-right · sheet covers ¾, canvas peeks above
The FAB fans out into one mini-button per category. Tap a category to jump straight to its sheet — fastest for "just change the size" or "just export". Most playful.
FAB ＋ fans up into category buttons; tap ✕ to close
A persistent bottom bar with the top categories + a center FAB for the primary action (Export). Tapping a tab raises its sheet. Most "native app" feel; controls always one tap away.
Bottom bar always visible · center FAB = Export
My lean: 1 · bottom sheet — simplest, reuses the exact same cards as desktop. 2 · speed-dial if quick per-category access matters. 3 · tab bar if you want it to feel like a native app.