tethys.backend/resources/js/Layouts/LayoutGuest.vue

<script setup>
import { StyleService } from '@/Stores/style';
const styleService = StyleService();
</script>

<template>
    <!-- dark; true or false from pinia service -->
    <div :class="{ dark: styleService.darkMode }">
        <div class="bg-gray-50 dark:bg-slate-800 dark:text-slate-100">
            <slot />
        </div>
    </div>
</template>