Dark Mode

Dark mode in vuecs is class-based: toggle .dark on <html> (or any ancestor of your component tree), and the design-system tokens in @vuecs/design flip automatically.

How it works

In assets/index.css:

css

:root {
    --vc-color-bg:           var(--color-white);
    --vc-color-fg:           var(--vc-color-neutral-900);
    --vc-color-border:       var(--vc-color-neutral-200);
    /* ... */
}

.dark {
    --vc-color-bg:           var(--vc-color-neutral-900);
    --vc-color-fg:           var(--vc-color-neutral-200);
    --vc-color-border:       var(--vc-color-neutral-800);
    /* ... */
}

Only the semantic aliases flip. The numeric scales (--vc-color-primary-500, etc.) stay the same — your primary blue is the same blue in both modes.

Components use bg-bg, text-fg, border-border (and their tokenized equivalents in non-Tailwind themes), so they all flip together.

Configuring the variant

In your stylesheet, add the dark variant if you want to author dark-specific overrides:

css

@import "tailwindcss";
@import "@vuecs/design";

@custom-variant dark (&:where(.dark, .dark *));

This makes dark:bg-primary-700 and friends work in your own classes. (Component packages don't need it — they read tokens, which flip on their own.)

Toggle in vanilla Vue

Roll your own toggle, or use @vueuse/core's useDark:

vue

<script setup>
import { useDark } from '@vueuse/core';
const isDark = useDark();
</script>

<template>
    <button @click="isDark = !isDark">
        {{ isDark ? '🌞' : '🌙' }}
    </button>
</template>

useDark adds/removes the .dark class on <html> automatically.

Toggle in Nuxt

@vuecs/nuxt ships its own useColorMode() composable, SSR-safe and cookie-backed:

vue

<script setup>
const { mode, resolved, isDark, toggle } = useColorMode();
</script>

<template>
    <button @click="toggle">{{ resolved === 'dark' ? '🌞' : '🌙' }}</button>
</template>

The composable is auto-imported. The vc-color-mode cookie persists the user's choice; the SSR plugin reads it and emits class="dark" on <html> before first paint, so there's no FOUC.

If you'd rather use @nuxtjs/color-mode, set vuecs: { colorMode: false } in nuxt.config.ts to opt out and wire it yourself.

See useColorMode for the full API.

Custom palettes in dark mode

The .dark flip only changes semantic aliases. To repalette the whole UI in dark mode (e.g. cooler blues, warmer accents), call setPalette() after <html> gains the .dark class:

import { setPalette } from '@vuecs/design';
import { watch } from 'vue';

watch(isDark, (dark) => {
    setPalette({
        primary: dark ? 'cyan' : 'blue',
    });
});

Next steps

Theme System guide — full resolution rules
Design Tokens guide — token chain, runtime palette switching
useColorMode — Nuxt composable reference

Dark Mode ​

How it works ​

Configuring the variant ​

Toggle in vanilla Vue ​

Toggle in Nuxt ​

Custom palettes in dark mode ​

Next steps ​