Cards on a phone

Cards are the part of Postroll a phone handles best — a card is already a portrait rectangle roughly the shape of a phone screen. Two of the five bottom tabs go straight to them: Create opens a new card, Cards opens yours.

Browsing — the Reel

The Reel is the phone-shaped way through a pile of cards: one card, full screen, swipe for the next. It works on your own library, the compendium, templates and the card feed.

1. Next / previous — swipe up and down.

2. Flip — tap the card to turn it over.

3. Actions — press and hold for the menu.

Reading a card in a grid

Anywhere cards appear as a grid, tapping one expands it in place. On a phone the expanded card scrolls inside itself, so the art stays at the top and the buttons at the bottom stay reachable no matter how much text the card carries.

Building a card

The studio keeps both panels — the design controls on one side, the card content on the other — but below 1280px they stop being fixed columns and become bottom sheets you open one at a time.

On a wide screen	On a phone or a narrow window
Two fixed panels either side of the card	Panels open as bottom sheets
Front, Back or Both at once	Front or Back — one side at a time
Drag handles sized for a cursor	Larger handles, sized for a fingertip

Why 1280 and not the usual breakpoint

The two panels are 380 and 360 pixels wide, and two editable cards need about 320 each. Below roughly 1280px something has to give, and shrinking the cards makes the one thing you are actually looking at too small to judge. So the panels move instead.

Everything the studio can do is available at phone width — this is a layout change, not a reduced feature set.

What is easier on a bigger screen

Comparing front and back side by side is a wide-screen luxury; a phone shows one face at a time and you flip between them. Fine adjustments to a card’s layout — nudging a block by a couple of pixels — are also more comfortable with a cursor. Neither is blocked on a phone, they are just slower.

Cards are light on memory now, on purpose

A deck of cards is a stack of large images, and phones are strict about how much decoded image they will hold at once. Card art is resized to the size it is actually shown at, and a swiper only paints the card you are looking at plus its immediate neighbours. If you have used the app on a phone in the past and had it reload itself while flicking through a deck, that is what was happening.