Macro sauron_core::prelude::jss_ns

macro_rules! jss_ns {
    ($namespace: tt, $($tokens:tt)+) => { ... };
}

Create a css string using json notation and use namespace on the class selectors

use jss::units::percent;
let css = jss::jss_ns!("frame3",
    ".": {
        display: "block",
    },

    ".layer": {
        background_color: "red",
        border: "1px solid green",
    },

    "@media screen and (max-width: 900px)": {
      ".layer": {
        width: percent(100),
      }
    },

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

let expected = r#".frame3{display:block;}.frame3__layer{background-color:red;border:1px solid green;}@media screen and (max-width: 900px){.frame3__layer{width:100%;}}.frame3__hide .frame3__layer{opacity:0;}"#;
assert_eq!(expected, css);