This example demonstrates a two-level single-page application without any module system, using plain JavaScript and XMLHttpRequest. Clicking a todo item in the overview renders its detail view, and clicking the detail title returns to the list. The app routes between overview and detail states via object-literal methods for routing, API calls, and rendering, fetching data from the JSONPlaceholder API. Global state is limited to a few object literals, with the DOM fully rebuilt on each render.