No more writing custom CSS for everything.
npm install -D tailwindcss postcss autoprefixer
Drupal 10, being a significant release, comes with a host of improvements and new features, especially concerning theme development. The modernization of theme development in Drupal 10 focuses on improving the developer experience, performance, and accessibility.
Instead of loading all CSS/JS globally, attach libraries only to the specific components rendered on the page. Drupal 10’s lazy-loading ensures that if a card component isn't on the page, its CSS isn't downloaded. modernizing drupal 10 theme development pdf
Vite (French for "fast") is the new standard. It offers:
Integration with Drupal:
The PDF contains a ready-to-use vite.config.js tailored for Drupal 10, including solving the hash filenames and relative path issues.
class Accordion extends HTMLElement
connectedCallback()
this.button = this.querySelector('button');
this.button.addEventListener('click', () => this.toggle());
customElements.define('custom-accordion', Accordion);
Then simply <custom-accordion> in your Twig template. No attach logic needed. Drupal’s BigPipe and Ajax are fully compatible because the browser handles the web component registration automatically. No more writing custom CSS for everything
The PDF includes a polyfill strategy for legacy browsers and a complete webcomponents.js boilerplate.