fixed InvalidAccessError when modifying html

src/index.jsx

@@ -1,24 +1,11 @@
 import "resources/nav/index.js"
 
-// https://stackoverflow.com/questions/1409225/changing-a-css-rule-set-from-javascript
-function getCSSRule(ruleName) {
-    ruleName = ruleName.toLowerCase();
-    var result = null;
-    var find = Array.prototype.find;
-
-    find.call(document.styleSheets, styleSheet => {
-        result = find.call(styleSheet.cssRules, cssRule => {
-            return cssRule instanceof CSSStyleRule 
-                && cssRule.selectorText.toLowerCase() == ruleName;
-        });
-        return result != null;
-    });
-    return result;
-}
-
 class SOGNavPlugin {
     initialize(registry, store) {
-        getCSSRule(".SOGNav__MenuItem").style.margin = "8px";
+        let elements = document.getElementsByClassName("SOGNav__MenuItem");
+        for (let i = 0; i < elements.length; i++) {
+            elements[i].style.margin = "8px";
+        }
     }
 }