Because Svelte just works with HTML directly, you can use any web component or HTML/CSS/JS based component. Below are some that I have found:

Pico CSS • Minimal CSS Framework for semantic HTML

shadcn-svelte

Tabler: Free and Open-Source HTML Dashboard Template

Flowbite Svelte - UI Component Library

daisyUI — Tailwind CSS Components ( version 4 update is here )

Tailwind UI - Official Tailwind CSS Components & Templates

Preline UI, crafted with Tailwind CSS

Melt UI

Introduction - Bits UI

Skeleton — UI Toolkit for Svelte + Tailwind

Web Components

Shoelace: A forward-thinking library of web components.

UX

Svelte UX