saving darkMode on localStorage

src/frontend/src/contexts/darkContext.tsx

@@ -13,13 +13,16 @@ const initialValue = {
 export const darkContext = createContext<darkContextType>(initialValue);
 
 export function DarkProvider({ children }) {
-  const [dark, setDark] = useState(false);
+  const [dark, setDark] = useState(
+    JSON.parse(window.localStorage.getItem("isDark")) ?? false
+  );
   useEffect(() => {
     if (dark) {
       document.getElementById("body").classList.add("dark");
     } else {
       document.getElementById("body").classList.remove("dark");
     }
+    window.localStorage.setItem("isDark", dark.toString());
   }, [dark]);
   return (
     <darkContext.Provider

src/frontend/src/pages/FlowPage/components/tabsManagerComponent/index.tsx

@@ -116,7 +116,7 @@ export default function TabsManagerComponent() {
           </button>
         </div>
       </div>
-      <div className="w-full h-full">
+      <div className="w-full h-full dark:bg-gray-800">
         <ReactFlowProvider>
           {flows[tabIndex] ? (
             <FlowPage flow={flows[tabIndex]}></FlowPage>