Accessible Modal and Drawer Behaviour
Make overlays trap focus, close predictably, and stay usable without a mouse.
What it adds
One shared overlay behaviour covering focus trapping, background inertness, escape handling, and scroll lock, applied to every modal, drawer, and popover panel in the app.
What your agent is told to do
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What your agent is told to do
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Find every overlay in the app — modals, drawers, sheets, command panels, image lightboxes — and route them through one implementation instead of fixing them individually.
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While an overlay is open, keep Tab and Shift+Tab cycling inside it and make the background inert so assistive technology cannot reach it. Hiding the background visually is not enough; a screen reader will still read straight through it.
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Give every overlay an accessible name from its visible title, and use dialog for things the user can dismiss versus alertdialog for interruptions that demand a decision.
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Lock background scrolling while open, compensating for the scrollbar width so the page does not shift sideways when the overlay appears.
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On close, return focus to whatever opened the overlay. If that trigger no longer exists — the row it lived in was deleted — fall back to a stable ancestor, and record the fallback rather than leaving it to chance.
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Do NOT let Escape close every open layer at once. It closes the topmost layer only, so a user dismissing a confirmation inside a drawer does not lose the drawer as well.
Edge cases it handles
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Edge cases it handles
7- An overlay with no focusable content still needs to receive focus itself, or the trap has nothing to hold.
- Content added after open — a lazily loaded form, an appended row — must be inside the trap without rebuilding it.
- Nested overlays need a stack: only the top layer is interactive, and closing it restores the trap to the layer beneath.
- On iOS, locking scroll by hiding overflow on the body is not sufficient and lets the page scroll behind the overlay.
- A drawer that pins open at desktop widths is no longer a dialog; it must stop trapping focus at that breakpoint.
- An overlay opened by a keyboard shortcut has no trigger element, so it needs an explicit return target.
- Closing must not depend on the backdrop existing — a full-bleed mobile sheet has no backdrop to click.
Definition of done
8
Definition of done
8- Every overlay in the app uses the same focus-trap and dismissal implementation.
- Tab cannot leave an open overlay, and assistive technology cannot reach the background.
- Escape closes only the topmost layer.
- Each overlay has an accessible name and the correct dialog or alertdialog role.
- Opening an overlay does not shift the page horizontally, and background scroll is locked including on iOS.
- Focus returns to the trigger on close, or to a defined fallback when the trigger is gone.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Focus Ring System
Focus Ring System
Give every focusable control one clear focus indicator that belongs to the design.
What it does
A single focus treatment applied consistently across buttons, links, inputs, cards, rows, and custom controls.
How it works
- 1 Inventory every focusable element in the app, including the ones made focusable by hand — clickable rows, cards, canvas objects, custom selects — and confirm each shows the shared treatment.
- 2 Distinguish focus arriving from the keyboard from focus arriving from a click, and show the ring for keyboard and programmatic focus. A ring appearing on every mouse press reads as a rendering fault and invites someone to remove it entirely.
- 3 Compose the ring so it stays visible on every surface the control can sit on: page background, card, coloured button, dark toolbar, selected row. A single-colour ring will disappear against at least one of them.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/focus-ring-system
Auto Captions
Auto Captions
Every uploaded video gets timed captions without anyone typing them out.
What it does
An automatic captioning pass over uploaded video that produces a timed caption track shown in the player.
How it works
- 1 Extend the app's existing Voice Transcription rather than adding a second speech pipeline. What is new here is timing, storage as a caption track, and player integration, not the recognition itself.
- 2 Run captioning as a background job triggered after the upload finishes, and reuse the app's existing job progress reporting so the user can see where a long file has got to.
- 3 Store the caption track as its own record linked to the media, with a language, a status, and a source marking it as machine-generated so a human correction can supersede it later.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/auto-captions
Touch Target Checker
Touch Target Checker
Find the controls that are too small or too crowded to hit reliably on a phone.
What it does
A development-time audit reporting the measured hit area and neighbour spacing of every interactive element.
How it works
- 1 Measure the element's actual activation area — the region that responds to a tap — rather than the icon or glyph drawn inside it, since padding and pseudo-element extensions frequently make a small icon a perfectly adequate target.
- 2 Check the gap between adjacent targets as well as their size. Two comfortable buttons sitting flush against each other still produce mis-taps, and the report must say which of the two problems it found.
- 3 Report the offending elements with enough context to locate them — the route, the component, and a way to highlight the element on the page — rather than a count of failures.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/touch-target-checker
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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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.