Theming

Nothing in a component says dark:, and nothing hardcodes a hex value. Every utility is built on tokens, so the whole system moves together.

Eight tones

Every tonal component takes the same tone prop.

anywhere

<Button tone="danger">Delete</Button>
<Badge tone="warning" dot>Quota</Badge>
<Alert tone="success" title="Deployed" />
<Progress tone="violet" value={40} />

brand accent violet info success warning danger neutral

Four steps each

Base, hover, light (a tinted surface) and border. Every one is a Tailwind utility: bg-accent, hover:bg-accent-hover, bg-accent-light, border-accent-border.

brand

accent

violet

info

success

warning

danger

neutral

theme.css

@theme {
	--color-brand: #1c6358;
	--color-brand-hover: #155047;
	--color-brand-light: #e8f3f1;
	--color-brand-border: #a8ccc5;
	/* …and the same four steps for the other seven tones */
}

Making it yours

Redeclare any token after importing the theme. Nothing else has to change — every component reading brand follows.

src/app.css

@import 'tailwindcss';
@import '@nqmcreative/ui/theme.css';

/* your brand, on top of the defaults */
@theme {
	--color-brand: #0f766e;
	--color-brand-hover: #115e59;
	--color-brand-light: #ecfdf5;
	--color-brand-border: #99f6e4;
}

Light and dark

The root element decides:

root	result
<html class="dark">	dark, explicitly chosen
<html class="light">	light, explicitly chosen
<html>	follows the OS preference

ThemeToggle writes that class and remembers the choice under nqm-theme:

anywhere

<script lang="ts">
	import ThemeToggle from '@nqmcreative/ui/theme-toggle';
</script>

<ThemeToggle />
<ThemeToggle variant="segmented" />

One light frame on first load

The class is applied after hydration, so someone who chose dark sees a light flash. The inline script in app.html from the installation page prevents it — and its key has to match what ThemeToggle writes.

In your own components

Import the tone maps rather than writing colour classes by hand.

MyThing.svelte

<script lang="ts">
	import { toneSoft, toneFill, type Tone } from '@nqmcreative/ui/tones';

	let { tone = 'brand' }: { tone?: Tone } = $props();
</script>

<div class={toneSoft[tone]}>…</div>

Never interpolate a class name

Tailwind only sees literal strings in your source. A constructed class silently produces no CSS.

the trap

<!-- Tailwind only sees literal class strings -->
<div class="bg-{tone}">…</div>          <!-- generates nothing -->
<div class={toneFill[tone]}>…</div>     <!-- correct -->

Adding a component →