Dark Mode
Add a dark theme that respects the system preference and the user's choice.
What it adds
A complete dark theme, defaulting to the operating system preference and overridable by the user.
What your agent is told to do
4
What your agent is told to do
4-
1
Audit every colour in the app first and report where they are defined. If colours are hardcoded throughout, extract them into tokens before anything else — that refactor is the bulk of this work.
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2
Define a dark palette against those tokens. Do not simply invert the light theme.
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3
Default to the system preference via prefers-color-scheme, and let the user override it.
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4
Persist the choice and apply it before first paint, so the page never flashes the wrong theme.
Edge cases it handles
4
Edge cases it handles
4- Images, logos, and illustrations with baked-in light backgrounds need dark variants or a background treatment.
- Third-party embeds and iframes will not follow your theme — handle them explicitly.
- Syntax highlighting, charts, and maps usually need their own dark themes.
- Re-check contrast in dark mode. Grey-on-grey passes design review and fails WCAG.
Definition of done
8
Definition of done
8- Every screen is legible in dark mode — no unstyled white panels.
- The theme follows the system preference by default.
- The user can override it and the choice persists across sessions.
- There is no flash of the wrong theme on load.
- Contrast meets WCAG AA in both themes.
- Images and embeds do not glare in dark mode.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Beautiful Empty States
Beautiful Empty States
Replace blank screens with useful, contextual empty states.
What it does
Every list, table, and dashboard in your app has a "nothing here yet" state. Most
apps ship a blank rectangle — and it is often the very first thing a new user sees.
An empty state should say what belongs here, why it is empty, and what to do next.
How it works
- 1 Inventory the empty cases first. List every collection view in the app and
- 2 Distinguish the three kinds of empty. They are not the same, and must not
- 3 Build one reusable empty-state component from the existing design system,
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/beautiful-empty-states
Countdown Timer
Countdown Timer
A live countdown to a deadline that ends cleanly instead of running negative.
What it does
A countdown component driven by a server-provided deadline, with a defined finished state.
How it works
- 1 Send the deadline and the server's current time together, compute the offset between server and device once, and count against the corrected value. The device clock cannot be trusted to be right.
- 2 Recompute the remaining time from the corrected clock on every tick rather than decrementing a stored number, so a suspended tab does not resume showing a value minutes behind reality.
- 3 Define the finished state explicitly: what the component shows at zero, whether it reveals something, disables a control, or triggers a refetch. Reuse the app's existing Progress Indicator System styling rather than introducing new type and colour for the digits.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/countdown-timer
Expandable Text
Expandable Text
Shorten long text without making the full content hard to reach.
What it does
Long text clamped to a few lines, with an explicit control to show the rest and collapse it again.
How it works
- 1 Clamp by rendered lines, not by character count. Cutting a string at a fixed length breaks words, mangles markup, and truncates differently at every width.
- 2 Only show the expand control when the text is genuinely clipped. A 'Show more' on a two-line paragraph is noise.
- 3 Use a real button with an accessible label naming what expands, and expose the expanded state. An untagged 'more...' is invisible to a screen reader.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/expandable-text
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.