Update js/index.js

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: RKBoss6

js/index.js

@@ -320,8 +320,9 @@ function iframeSetup(options) {
     // Style custom apps for dark mode
     const iframeDoc = iframe.contentDocument || iframe.contentWindow.document;
     if (iframeDoc && iframeDoc.body) {
-      const bgColor = window.matchMedia('(prefers-color-scheme: dark)').matches ? '#2c2c2c' : '#ffffff';
-      const textColor = window.matchMedia('(prefers-color-scheme: dark)').matches ? '#FFFFFF' : '#000000';
+      const prefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
+      const bgColor = prefersDark ? '#2c2c2c' : '#ffffff';
+      const textColor = prefersDark ? '#FFFFFF' : '#000000';
       iframeDoc.body.style.backgroundColor = bgColor;
       iframeDoc.body.style.color = textColor;
     }