Radius Scale

Fix the app's corner radii to a few steps that agree with one another.

simple Design Systems

What it adds

A small radius scale mapped to component roles — controls, cards, overlays, pills, media — and applied throughout.

What your agent is told to do

1
Collect every corner radius in the codebase and reduce it to three or four steps, then assign each step a role: controls and inputs, cards and panels, overlays and sheets, fully rounded pills.
2
Set nested radii so the inner corner is smaller than the outer one by roughly the padding between them. An inner element with the same radius as its container leaves a visible sliver of gap at each corner.
3
Scale the radius with the component: the step that reads as softly rounded on a small button reads as barely rounded on a large panel, and as a lozenge on a short chip.
4
Reserve the fully rounded step for shapes it suits — chips, tags, avatars, counters — and keep it off anything tall or wide enough for the curve to eat its content. Do not apply a pill radius to a multi-line container, where the ends bulge and the text no longer sits inside the shape.
5
The Spacing Scale entry owns the padding values; this entry owns the corners. Where a nested radius depends on padding, read the spacing token rather than restating the number here.

Edge cases it handles

Nesting a rounded element inside another rounded element with the same value produces a mismatched corner and a visible gap. Derive the inner radius from the outer one and the padding between them.
A fully rounded radius on a tall or multi-line element turns it into a lozenge with unusable corners. Restrict the pill step to elements whose height stays close to a single line.
One radius across every size is wrong at both ends. Map larger components to larger steps so the curve stays proportionally the same rather than numerically the same.
Clipping a container to round its corners will also clip focus rings, shadows, tooltips, and dropdowns that need to escape it. Round the media or the inner surface rather than the container that holds an overlay.
A theme with zero radius must still work: nothing may depend on the curve to separate two surfaces, or the flat theme will read as a single undifferentiated block.
Grouped controls — segmented buttons, split buttons, joined inputs, table corners — need per-corner radii so only the outer edges of the group are rounded.
Circular avatars and pill shapes are different intentions that happen to share a value. Name them separately so changing one does not silently change the other.

Definition of done

The app uses three or four radius steps, each mapped to a documented component role.
Nested elements use an inner radius derived from the outer radius and the intervening padding.
Radius scales with component size rather than one value applied at every scale.
The fully rounded step appears only on single-line or circular shapes.
Focus rings, shadows, and overlays are not clipped by a rounded container.
A zero-radius theme renders with every surface boundary still legible.
Grouped controls round only the outer corners of the group.
The feature matches the existing design system.
No existing functionality is broken.

Related features

Z-Index Registry

Shadow Scale

Spacing Scale

How it works

1

Copy the link

Grab the Markdown instruction URL for this feature.
2

Give it to your AI

Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
3

It inspects, then implements

Your agent reads your existing app first, then adds the feature to fit it.

Works with your stack

These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.

Need it tighter than that? Customize the feature and tell it exactly what you're running.