This is a Clojurescript wrapper of JSS. Please see their repo for extensive documentation.
(ns demo.core
(:require [reagent.core :as reagent]
[cljss.core :as cljss]))
(cljss/setup)
(def styles {:container {:color :blue
:font-family :papyrus}
"@media (max-width: 800px)"
{:container {:color :red}}})
(defn- component []
(let [classes (cljss/classes styles)]
[:div {:className (:container classes)}
"Hello, World!"]))
(defn mount-root []
(reagent/render [component]
(.getElementById js/document "reagent-app")))
(defn init []
(mount-root))