Surface patterns in production, turn them into evals, and improve quality with every release.
Capture inputs, outputs and intermediate steps for every agent execution.
Run evals continuously and compare across model and prompt versions.
Cluster production failures into topics you can act on.
Controls are 40px tall at 0 16px padding with a 24px pill radius and an 18px/400 label; the primary fill is #2c1fea. Disabled is a real token, #7e95fc at opacity .5–.6, not just a fade.
Accessibility note: the real site suppresses its focus ring (focus-visible:ring-0 and outline-hidden). That is recorded in DESIGN.md as an anti-pattern, so the focus state shown above is a recommended replacement (3px #7e95fc ring), not a reproduction. Do not copy the suppressed ring.
Specimens substitute Space Grotesk for the custom btSans and JetBrains Mono for suisseMono; Inter is the real face. Note the 1:1 line-height at display sizes and that nav is the heaviest text on the page.
There is no shadow scale — across ~5,000 elements the only box-shadow is a transparent ring reset, so depth is band colour plus a 1px border that swaps colour with the band. Motion is opacity-led: 0.15s cubic-bezier(.4,0,.2,1) on 206 elements, with a slow 0.7s cubic-bezier(0,0,.2,1) for large panel reveals. Table keyframes columnFlash and rowFlash highlight data cells; slow-stripes runs 2s infinite. Two prefers-reduced-motion blocks are honoured, and 21 container queries size the data components.