Grabbed dndbeyond's source code

```
~/go/bin/sourcemapper -output ddb -jsurl https://media.dndbeyond.com/character-app/static/js/main.90aa78c5.js
```

ddb_main/node_modules/jss-plugin-template/dist/jss-plugin-template.esm.js

@@ -0,0 +1,45 @@
+import warning from 'tiny-warning';
+
+var semiWithNl = /;\n/;
+/**
+ * Naive CSS parser.
+ * - Supports only rule body (no selectors)
+ * - Requires semicolon and new line after the value (except of last line)
+ * - No nested rules support
+ */
+
+var parse = function parse(cssText) {
+  var style = {};
+  var split = cssText.split(semiWithNl);
+
+  for (var i = 0; i < split.length; i++) {
+    var decl = (split[i] || '').trim();
+    if (!decl) continue;
+    var colonIndex = decl.indexOf(':');
+
+    if (colonIndex === -1) {
+      process.env.NODE_ENV !== "production" ? warning(false, "[JSS] Malformed CSS string \"" + decl + "\"") : void 0;
+      continue;
+    }
+
+    var prop = decl.substr(0, colonIndex).trim();
+    var value = decl.substr(colonIndex + 1).trim();
+    style[prop] = value;
+  }
+
+  return style;
+};
+
+var onProcessRule = function onProcessRule(rule) {
+  if (typeof rule.style === 'string') {
+    rule.style = parse(rule.style);
+  }
+};
+
+function templatePlugin() {
+  return {
+    onProcessRule: onProcessRule
+  };
+}
+
+export default templatePlugin;