Everything in the store

A mechanical pass over a running website or web app in a real browser -- console, network, images, layout at five widths, links, forms and contrast -- with the exact numbers that count as pass or fail. Use before reporting any page, site or web app as done, and after changing one.

The values and rules that make a website or web app work on phones -- viewport, breakpoints, tap target and font minimums, safe areas, dynamic viewport height, touch-only interaction and the layout patterns that hold up at 360px. Use when building any page that people may open on a phone, or when a site looks wrong on mobile.

A complete visual direction for websites and web apps -- type scale, spacing, colour, layout and component values, plus the defaults that make a page look machine-made. Use when building or restyling any page, site, landing page, dashboard or front end, before writing CSS.

Finding the cause of a failure in a web app, script or server -- what to capture first, a table of common symptoms and the causes they usually mean, and how to prove a fix. Use when something errors, crashes, returns the wrong result, works locally but not when served, or an application reports trouble.

The questions worth asking before building something for someone -- a short bank per kind of project, how to tell a question that changes the build from one that does not, and the defaults to use for whatever goes unasked. Use when a request to build a site, app, tool, store or automation is short or leaves out who it is for, what it must do, or where it will run.