Build with the web.
Drive it with Python.

from ultralight_py import API, Application

with API("app") as api, Application() as app:

    @api.register
    def hello(name):
        return f"Hello, {name}!"

    window = app.create_window(800, 520, title="Hello, ultralight-py")
    api.attach(window.view)
    window.view.load_html("""
        <style>
          body { background: #111315; color: #edb584;
                 font: 24px system-ui; padding: 48px; }
        </style>
        <h1 id="hello"></h1>
        <script>
          document.querySelector('#hello').textContent = app.hello('world');
        </script>
    """)
    app.run()