Add minified css files

build/build-css.js

@@ -0,0 +1,20 @@
+var fs = require('fs')
+var cssnano = require('cssnano').process
+var resolve = require('path').resolve
+
+var save = function (file, content) {
+  fs.writeFileSync(resolve(__dirname, '../lib/themes/', file), content)
+}
+var load = function (file) {
+  return fs.readFileSync(resolve(__dirname, '../themes/', file)).toString()
+}
+
+var list = fs.readdirSync(resolve(__dirname, '../themes'))
+
+list.forEach(function (file) {
+  cssnano(load(file))
+    .then(function (result) {
+      save(file, result.css)
+      console.log('cssnao - ' + file)
+    })
+})