diff --git a/src/App.tsx b/src/App.tsx
index b9083ca..37c1ebd 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -2,8 +2,8 @@ import { useEffect } from "react";
 import { FloorPlan } from "./components/FloorPlan";
 import { HeaderBar } from "./components/HeaderBar";
 import { SidePanel } from "./components/SidePanel";
-import { startRuntime } from "./sim/runtime";
-import { useOfficeStore } from "./store/office-store";
+import { setMode, startRuntime } from "./sim/runtime";
+import { loadPreferredMode, useOfficeStore } from "./store/office-store";
 
 export default function App() {
   const theme = useOfficeStore((s) => s.theme);
@@ -11,6 +11,7 @@ export default function App() {
 
   useEffect(() => {
     startRuntime();
+    if (loadPreferredMode() === "live") setMode("live");
   }, []);
 
   return (
diff --git a/src/store/office-store.ts b/src/store/office-store.ts
index ee5075a..648fb83 100644
--- a/src/store/office-store.ts
+++ b/src/store/office-store.ts
@@ -71,25 +71,60 @@ interface OfficeState {
 
 let eventSeq = 0;
 
+/* UI preferences persisted across reloads. */
+function loadPref(key: string): string | null {
+  try {
+    return localStorage.getItem(key);
+  } catch {
+    return null;
+  }
+}
+
+function savePref(key: string, value: string) {
+  try {
+    localStorage.setItem(key, value);
+  } catch {
+    /* ignore */
+  }
+}
+
+const savedTheme = loadPref("office-theme");
+const savedPanel = loadPref("office-panel");
+
+/** Read the preferred data source ("live" | "sim"); the runtime applies it on boot. */
+export function loadPreferredMode(): "sim" | "live" {
+  return loadPref("office-mode") === "live" ? "live" : "sim";
+}
+
 export const useOfficeStore = create<OfficeState>()((set, get) => ({
   agents: new Map(),
   links: [],
   meetings: [],
   events: [],
   selectedAgentId: null,
-  theme: "light",
+  theme: savedTheme === "dark" ? "dark" : "light",
   paused: false,
   speed: 1,
   mode: "sim",
-  panelOpen: true,
+  panelOpen: savedPanel !== "0",
   clock: 0,
 
   selectAgent: (id) => set({ selectedAgentId: id }),
-  setTheme: (t) => set({ theme: t }),
+  setTheme: (t) => {
+    savePref("office-theme", t);
+    set({ theme: t });
+  },
   setPaused: (p) => set({ paused: p }),
   setSpeed: (s) => set({ speed: s }),
-  setMode: (m) => set({ mode: m }),
-  togglePanel: () => set((state) => ({ panelOpen: !state.panelOpen })),
+  setMode: (m) => {
+    savePref("office-mode", m);
+    set({ mode: m });
+  },
+  togglePanel: () =>
+    set((state) => {
+      savePref("office-panel", state.panelOpen ? "0" : "1");
+      return { panelOpen: !state.panelOpen };
+    }),
   clearWorld: () =>
     set({ agents: new Map(), links: [], meetings: [], events: [], selectedAgentId: null }),