Annual Letter.

Stripe-annual-letter style single-file HTML decks: cream #FBFAF8 paper with a single Stripe-purple #635BFF accent, serif prose paragraphs at a 65ch publication measure, inline data cards embedded in the running text, and oversized tabular display-number anchor pages — the 'editorial longform' letter genre, prose flow instead of bullets. Based on alchaincyf/huashu-design editorial-longform (design-styles.md 安静派 · Editorial Longform).