When you see the complex machinery developed in Brython and How-Brython-works, transposing into javascript the Python code with one more syntax to digest, we could still hope for a direct approach based on the javascript engine that works by default in web browsers, and respecting as closely as possible the existing syntaxes of the DOM, HTML, CSS, ... as a slight overlay over existing web technologies.
It's the quest of the {lambda way} project.