Shadow and back.

The shadow

The sticky header bar — the one that says 531. ledger and stays pinned at the top — now casts a small drop shadow when you’ve scrolled down on any page with content above the fold. The shadow is deliberately light: just enough to signal “there’s content behind this” without reading as a card lift from a different design language.

The shadow disappears when you’re at the top of the page, where there’s nothing above to cast a shadow for.

Settings and History got the shadow this iteration. Progress is deferred — its carousel has a more complex scroll setup, and getting the elevation state to the shared header takes a bit more plumbing. The decision log has the path forward if the user notices.

The back

If back on Home screen, exit app. If back on any other nav screens, return to home screen. If back on any child screen from a nav screen, history should pop.

The previous behavior: Android’s hardware back button went to whichever tab you’d visited before the current one. Visit History, then Settings, then press back — lands on History. That’s “history” in the navigator’s sense, and exactly what the user did not want.

The fix is a one-setting change in the tab navigator. Now:

• On Today (the home tab): hardware back exits the app.
• On any other tab: hardware back goes to Today.
• On a screen pushed on top of a tab (a drill-down from History, for example): hardware back pops back to that tab.

That matches the user’s three-line spec exactly.

— Margin