van-hmr/app.js

const CSS = Gale({
    Button:{
        padding: "20px",
        background: "blue",
        borderRadius: "20px",
        color: "white",
        fontWeight: "bolder",
        ":hover":{
            background: "yellow"
        }
    }
});

const state = vanX.reactive({key1:"value1", key2:"value2", count:7}, "THING")
console.log(state);

van.add
(
    document.body,
    van.tags.div
    (
        {
            class:CSS("Button"),
            onclick()
            {
                state.count++;
            }
        }
        , ()=>state.count
    )
);