fix: improve tabbable performance

src/internal/tabbable.ts

@@ -1,5 +1,8 @@
-import { offsetParent } from 'composed-offset-position';
-
+// It doesn't technically check visibility, it checks if the element has been rendered and can maybe possibly be tabbed to.
+// This is a workaround for shadowroots not having an `offsetParent`
+function isTakingUpSpace (elem: HTMLElement): boolean {
+  return Boolean( elem.offsetParent || elem.offsetWidth || elem.offsetHeight || elem.getClientRects().length );
+}
 /** Determines if the specified element is tabbable using heuristics inspired by https://github.com/focus-trap/tabbable */
 function isTabbable(el: HTMLElement) {
   const tag = el.tagName.toLowerCase();
@@ -20,8 +23,8 @@ function isTabbable(el: HTMLElement) {
   }
 
   // Elements that are hidden have no offsetParent and are not tabbable
-  // offsetParent() is added because otherwise it misses elements in Safari
-  if (el.offsetParent === null && offsetParent(el) === null) {
+  // !isRendered is added because otherwise it misses elements in Safari
+  if (!isTakingUpSpace(el)) {
     return false;
   }