The "Éléments de cet écran" tree now sits above "Ajouter un élément sur l'écran" / "Mes éléments de jeu" so it's the first thing visible in the left panel. Each container row gets a disclosure triangle that collapses/expands its children, independent from the row's link (which still selects the element and shows its properties whether collapsed or expanded). The collapsed state is remembered per element in localStorage. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>