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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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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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
Semantic Color Tokens
Semantic Color Tokens
Name colours by the job they do, so changing a theme is one edit rather than a sweep.
What it does
A vocabulary of role-named colour tokens — surface, text, border, accent, danger, success — that components reference instead of literal values.
How it works
- 1 Inventory every literal colour value in the codebase and group them by the job they are doing rather than by the shade they happen to be. Two different greys used as card backgrounds are one role; the same grey used as a background and as a border is two.
- 2 Define the role names once and map each role to a value per theme. A role may resolve to a light grey in one theme and a near-black in another; what must not change is which components reference it.
- 3 Stop shared components accepting raw colour values. A primitive that takes a hex string as a prop guarantees that some product screen will hardcode a colour the themes never learn about.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/semantic-color-tokens
Motion Token System
Motion Token System
Give the app one shared vocabulary of durations and easing curves instead of ad hoc numbers.
What it does
A named set of durations and easing curves, each tied to a category of motion, replacing the timing values scattered through the app's components.
How it works
- 1 Inventory every duration and easing value currently written into the app and group them by what they do: something entering, something leaving, something being emphasised, and something changing size or position.
- 2 Name a small set of durations — roughly instant, quick, standard, and deliberate — and a small set of curves, then map each motion category to a pairing. Four or five of each is enough for an entire product.
- 3 Give entrances and exits different treatment. Something arriving should decelerate into place; something leaving should accelerate away and take less time, because nobody wants to wait for a dismissal.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/motion-token-system
Responsive Grid Tokens
Responsive Grid Tokens
Express columns, gaps, and spans as shared tokens rather than per-component guesses.
What it does
A token set describing column counts, gutters, and span behaviour at each breakpoint, used by every grid in the app.
How it works
- 1 Find the grids already in the app — card lists, dashboards, form layouts, media galleries — and record how many columns each uses at each size. The reconciled set is normally three or four column counts, not one per screen.
- 2 Define gutters from the spacing scale rather than inventing grid-specific values, so the gap between cards matches the rhythm of everything around them.
- 3 Express spans in tokens tied to the column count, so a component asking for half a row keeps working when the row drops from four columns to two instead of overflowing.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/responsive-grid-tokens
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.