Safe Sticky Positioning
Make sticky headers, bars, and panels behave consistently and stop fighting each other.
What it adds
One shared approach to sticky elements, with a single source of truth for offsets and reserved space.
What your agent is told to do
5
What your agent is told to do
5-
1
Inventory every element meant to stay put while its surroundings scroll — page headers, table header rows, section titles, filter bars, side panels, action bars — and route them all through one shared arrangement instead of the several that exist. The bottom-edge case is owned by Sticky Action Bar; this brief owns the mechanism and the offset arithmetic it draws on.
-
2
Keep a single source of truth for stacked offsets, so a header, a sub-header, and a sticky table row each know the measured height of what sits above them. A hardcoded pixel offset per screen guarantees drift the first time the header changes height.
-
3
Reserve the space a sticky element will occupy before it detaches, so nothing jumps at the moment it changes behaviour and no content is left hidden underneath it.
-
4
Below the narrow breakpoint, decide per element whether it stays, collapses to a smaller form, or unsticks entirely. On a short screen three stuck bars leave almost no room for the content they are framing.
-
5
Do not apply sticky positioning inside an ancestor that clips or scrolls its own overflow — the element will either be trapped or disappear. Detect that case during the audit and either fix the ancestor or move the element out of it.
Edge cases it handles
7
Edge cases it handles
7- An ancestor with hidden or scrolling overflow silently breaks sticky positioning, and the symptom — an element that stays put on one page and scrolls away on another — is easy to misdiagnose as a styling problem.
- Without reserved space the page shifts by the element's height at the instant it sticks, which moves whatever the user was about to click.
- Two sticky elements that both claim the top edge will overlap. Offsets have to derive from measured heights so that a wrapping header or an incident banner pushes everything below it down.
- On a short viewport sticky chrome can consume most of the usable height, so measure the real visible area rather than assuming the window height, particularly with an on-screen keyboard open.
- Anchor navigation and in-page links must offset their scroll target by the sticky height, or the heading being jumped to lands underneath the header.
- Keyboard focus moving to an element just below a sticky header must not leave that element obscured; scrolling into view has to account for the occluded strip.
- A sticky element with a transparent or blurred background shows content sliding beneath it, which needs a deliberate treatment rather than being discovered in review.
Definition of done
8
Definition of done
8- All sticky elements share one mechanism and one source of offsets.
- Stacked sticky elements never overlap, whatever height the header takes.
- Nothing shifts when an element transitions into or out of its stuck state.
- No sticky element sits inside an ancestor that clips or scrolls its overflow.
- Sticky behaviour is defined explicitly for narrow and for short viewports.
- Anchor links and focus scrolling land below the sticky chrome rather than under it.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Feedback Widget
Feedback Widget
Let anyone report a bug or send a comment from the page they are looking at.
What it does
An always-available launcher that opens a short feedback form and submits it with page context attached.
How it works
- 1 Put a single persistent launcher in one corner of the app and open a compact form in place. Do not route the user to a separate feedback page and lose the context they were about to describe.
- 2 Attach the current URL, the app version, the viewport size, the signed-in account, and a short trail of recent client errors automatically, so the reporter does not have to describe where they were.
- 3 Show the captured context to the user before they send it, in a collapsible section, and let them remove it. Silent collection of screen state is a trust problem.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/feedback-widget
Booking Page
Booking Page
A shareable page where someone picks an open time and confirms it in a few clicks.
What it does
A public scheduling page listing open slots, taking a booking, and confirming it to both sides.
How it works
- 1 Build the visitor path first: pick a date, see open times in their own zone, fill a short form, confirm, and receive an email with the details and a cancellation link. That is the minimum coherent version.
- 2 Derive open slots from the owner's availability rules and existing bookings on the server at request time. Do not trust a slot list the browser has been holding since page load.
- 3 Reuse the app's existing Time Zone-Aware Scheduling for conversion and storage, store every time as an absolute instant, and display it converted to the visitor's detected zone with the zone named on screen.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/booking-page
Date and Time Display Component
Date and Time Display Component
Render every date and time through one component so none of them are ambiguous.
What it does
A single shared way of displaying dates and times, covering absolute format, time zone, and optional relative phrasing.
How it works
- 1 Find every place the app renders a date or a time — tables, activity feeds, audit logs, exports, emails, tooltips — and route them all through one display path rather than formatting at each call site.
- 2 Never render an all-numeric date whose day and month could be swapped. Spell or abbreviate the month, or use an unambiguous ordering consistently, because a reader has no way to tell 04/07 from 07/04.
- 3 State the time zone whenever the value is a specific moment rather than a calendar day, and be explicit about whose zone it is — the viewer's, the record's, or the account's — rather than leaving it implied.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/date-and-time-display-component
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.