document.getElementById("start-btn")?.addEventListener("click", async () => { const authComponent = document.querySelector("auth-component"); if (!authComponent) return; const isLoggedIn = await ( authComponent as { isAuthenticated: () => Promise } ).isAuthenticated(); if (isLoggedIn) { window.location.href = "/classes"; } else { (authComponent as { openAuthModal: () => void }).openAuthModal(); } });