• ✓Idea: serial sevens, with the clock taken out
• ✓The method first: down to the ten, then the rest (93 − 3 = 90, then 90 − 4 = 86)
• ✓Every helper sentence is arithmetically checked — npm run verify:countback
• ✓Keys ≥60px, text 18px and up, nothing red — Silver rules
• ✓A physical keyboard works too; Enter answers
• ✓EQ: the second miss buys the method, not another no — and two helped steps offers a gentler ladder with no apology in it
• ✓A counting-up mode, for a day that wants something easyplanned

✓ = done · ☐ = planned. Every game is built one step at a time like this.