in src/focus-zone.ts [627:636]
function getCurrentFocusedIndex() {
if (!currentFocusedElement) {
return 0
}
const focusedIndex = focusableElements.indexOf(currentFocusedElement)
const fallbackIndex = currentFocusedElement === container ? -1 : 0
return focusedIndex !== -1 ? focusedIndex : fallbackIndex
}