A hero image for CallBook, an app where traders publish sealed price calls that are later settled on chain, so their track record cannot be faked or deleted.

Exactly 1600x900 pixels, PNG, wide.

Scene: a dark trading desk at night. In the centre, a thick leather-bound ledger lies open; its pages show glowing candlestick charts. A wax-sealed envelope rests on the left page (a sealed call), and on the right page a price line crosses a dotted target line with a small green check mark where it hits.

Style: cinematic digital illustration, moody, deep navy and charcoal tones with a single accent colour, mint green (#3fcf7f). No people, no logos of real companies, no coin symbols.

Text: the word CALLBOOK in large clean capital letters at the top left, and under it, smaller: Calls you can't delete. Spell both exactly like this; no other text anywhere in the image.