Enhance modal functionality with ModalContainer component; update ShareModal to use ModalWrapper; improve responsive text sizes in index.css; integrate FloatingActionButton in HomePage for popup sharing.

client/src/store/modalStore.ts

@@ -0,0 +1,18 @@
+import { create } from "zustand";
+import type { ReactNode } from "react";
+
+interface ModalState {
+  modal: ReactNode | null;
+  setModal: (modal: ReactNode | null) => void;
+  position: "center" | "right";
+  setPosition: (position: "center" | "right") => void;
+}
+
+const useModalStore = create<ModalState>()((set) => ({
+  modal: null,
+  position: "center",
+  setPosition: (position) => set({ position }),
+  setModal: (modal) => set({ modal }),
+}));
+
+export default useModalStore;