[V1] Patched MangaPreview & Added Themes (Contrast)

src/App.tsx

@@ -85,6 +85,11 @@ export default function App() {
     document.documentElement.style.zoom = `${settings.uiScale * 1.5}%`;
   }, [settings.uiScale]);
 
+  useEffect(() => {
+    const theme = settings.theme ?? "dark";
+    document.documentElement.setAttribute("data-theme", theme);
+  }, [settings.theme]);
+
   useEffect(() => {
     const p = (e: MouseEvent) => e.preventDefault();
     document.addEventListener("contextmenu", p);