Hallmark is a free skill that catches the AI “design slop” tells before you ship

Each of the 48 presets is a full “material,” its own components and texture rather than a single color swap, and the skill supports custom styles too: ask for something outside the presets and Hallmark designs from the prompt directly under the same underlying rules.

The browser check, called sloplint, renders the page at eight different widths and then hands it to a fresh-context subagent for review, a reviewer with no memory of how the page was built, just what it looks like. The checks target specific machine-made tells: an eyebrow label sitting above every heading, tracked-capital text, a single colored word buried in a headline, pages built from empty placeholder frames or nothing but stock photography, a hero section that spills past the first screen, a sign-up form parked at the bottom of every page, or a “thank you” message that fires without the form actually submitting anything.

The checks are organized into three tiers. Floor gates never ship past, no matter what, covering contrast, focus states, reduced motion, invented facts, and broken phone layouts. Reflex gates catch the default habits models fall into, and a build can override one if it logs a reason for doing so. Finish checks cover craft-level polish and never block a release outright. Worth being precise here: the README describes sloplint as a linter that flags issues in the browser, not a tool that edits the page itself, the actual fixing still happens through the coding agent’s normal workflow afterward.

The redesign mode has its own separate check built around not losing anything in the process: sloplint records every link, form field, handler, and heading on the existing page before touching it, then fails the whole redesign outright if any of them go missing afterward. That’s a narrower, more mechanical kind of check than the visual gates, but it’s the one most likely to save someone from shipping a prettier page that quietly broke a contact form or dropped a navigation link nobody noticed was gone.