AddThisFeature

Dark Mode

Add a dark theme that respects the system preference and the user's choice.

moderate UI & Polish

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
  1. 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.

  2. 2

    Define a dark palette against those tokens. Do not simply invert the light theme.

  3. 3

    Default to the system preference via prefers-color-scheme, and let the user override it.

  4. 4

    Persist the choice and apply it before first paint, so the page never flashes the wrong theme.

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
  • 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

How it works

  1. 1

    Copy the link

    Grab the Markdown instruction URL for this feature.

  2. 2

    Give it to your AI

    Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.

  3. 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.