Macro jss 

macro_rules! jss {
    ($($tokens:tt)+) => { ... };
}

Creates css using json notation

use jss::jss;
let css = jss!(
    ".layer": {
        background_color: "red",
        border: "1px solid green",
    },

    ".hide .layer": {
        opacity: 0,
    },
);

let expected =
    r#".layer{background-color:red;border:1px solid green;}.hide .layer{opacity:0;}"#;
assert_eq!(expected, css);