Z-Index Registry
Keep every stacking value in one file so nobody has to guess a bigger number.
What it adds
A single source of named z-index tokens, with reserved ranges per layer and a check that blocks raw values.
What your agent is told to do
5
What your agent is told to do
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1
Find every z-index in the codebase, including inline styles and values buried in third-party overrides, and list them with the component that owns each. The count is usually higher than anyone expects and several will be arbitrary large numbers.
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2
Reserve a range for each layer rather than assigning single values, so a new dropdown can slot between existing ones without renumbering everything above it. Leave real gaps between ranges.
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Name each token after the layer it belongs to and derive the ordering from Elevation Layer Map. That feature decides what covers what; this one holds the numbers and stops them being invented locally.
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4
Add a check that fails when a raw numeric z-index appears outside the registry, and run it in the same place the rest of the style rules are enforced. Without it the registry decays within a release or two.
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5
Do not fix a stacking bug by raising a number. If an overlay renders behind something despite a higher value, the cause is a local stacking context and raising it further only hides the problem until the next collision.
Edge cases it handles
7
Edge cases it handles
7- Ranges must be reserved per layer with room to grow, because a scheme of consecutive integers forces a rename of every higher token the first time something new needs to sit in the middle.
- A component whose value is correct but which still renders underneath is trapped in an ancestor's stacking context created by a transform, filter, or opacity. The check should surface that case rather than leaving developers to escalate numbers.
- Genuine exceptions exist — third-party widgets, embedded players, payment iframes that insist on their own values — and each needs a named token with a comment recording why, rather than an unexplained outlier.
- The lint has to cover inline styles and dynamically computed values, not only static stylesheets, or the values simply move to where the check cannot see them.
- Negative z-index places an element behind its own parent's background and is almost never what was intended; treat it as a case requiring explicit justification.
- Third-party scripts injected at runtime can set values above anything the registry defines, so the top of the range needs headroom and a documented response.
- Elements in the browser's native top layer are outside the registry's control entirely, and the registry should say so rather than implying it governs them.
Definition of done
8
Definition of done
8- Every z-index in the app resolves to a named token in one registry file.
- Layers occupy reserved numeric ranges with gaps left for insertion.
- A check fails the build on any raw z-index outside the registry, including inline styles.
- The registry's order matches the ordering defined by Elevation Layer Map.
- Each exception carries a named token and a recorded reason.
- No stacking bug in the app is resolved by an arbitrarily large number.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Spacing Scale
Spacing Scale
Reduce the app's spacing to a small set of steps that repeat across every surface.
What it does
A named spacing scale covering gaps, padding, and section rhythm, with every existing value in the app mapped onto it.
How it works
- 1 Collect every spacing value currently in the codebase and count how often each appears. The result is usually a handful of genuine intentions surrounded by dozens of near-misses that were nudged once and never revisited.
- 2 Define a scale that is fine at the small end, where control padding lives, and coarse at the large end, where section separation lives. A linear scale gives too many indistinguishable large steps and too few small ones.
- 3 Separate the tokens used inside a component from the ones used between components and between page sections, and name them so the difference is obvious. The same number serving both purposes means a change to button padding also changes the gap between sections.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/spacing-scale
Shadow Scale
Shadow Scale
Replace ad hoc shadows with a small set tied to what each surface actually is.
What it does
A fixed ladder of shadow tokens, each named for an elevation role rather than a blur radius.
How it works
- 1 Collect every shadow currently declared anywhere in the app and group them by what they sit on — a resting card, a hovered card, a dropdown, a dialog, a toast. Most apps have a dozen near-identical values that collapse into four or five roles.
- 2 Name each step for its role, not its appearance. A token called menu tells the next person which surfaces may use it; a token called shadow-md-2 does not.
- 3 Use a single light source for the whole scale, so offset, blur, and spread grow together as elevation rises. Two shadows lit from different directions on the same screen read as a rendering bug.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/shadow-scale
Radius Scale
Radius Scale
Fix the app's corner radii to a few steps that agree with one another.
What it does
A small radius scale mapped to component roles — controls, cards, overlays, pills, media — and applied throughout.
How it works
- 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.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/radius-scale
How it works
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1
Copy the link
Grab the Markdown instruction URL for this feature.
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2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
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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.