diff --git a/app/src/App.tsx b/app/src/App.tsx
index 07f592c..8169f28 100644
--- a/app/src/App.tsx
+++ b/app/src/App.tsx
@@ -5,6 +5,7 @@ import { TopBar } from "./TopBar";
 import { CenterToolbar } from "./CenterToolbar";
 import { Wizard } from "./Wizard";
 import { ConfirmDelete } from "./ConfirmDelete";
+import { Settings } from "./Settings";
 import { EventCenter } from "./EventCenter";
 import { maybeNotify } from "./notify";
 import { COLORS, applyTheme, resolvePalette } from "./theme";
@@ -31,6 +32,7 @@ export function App() {
   const [events, setEvents] = useState<EventRecord[]>([]);
   const [wizard, setWizard] = useState(false);
   const [deleteTarget, setDeleteTarget] = useState<WorkspaceView | null>(null);
+  const [settingsOpen, setSettingsOpen] = useState(false);
   const [eventsOpen, setEventsOpen] = useState(() => loadFlag("spacesh.eventsOpen", true));
   const [sidebarOpen, setSidebarOpen] = useState(() => loadFlag("spacesh.sidebarOpen", true));
   const [health, setHealth] = useState<DaemonHealth | null>(null);
@@ -147,7 +149,7 @@ export function App() {
 
   return (
     <div style={{ display: "flex", flexDirection: "column", height: "100vh", background: COLORS.bgApp }}>
-      <TopBar active={active} eventsOpen={eventsOpen} onToggleEvents={() => setEventsOpen((v) => !v)} onShowEvents={() => setEventsOpen(true)} sidebarOpen={sidebarOpen} onToggleSidebar={() => setSidebarOpen((v) => !v)} unread={unread} />
+      <TopBar active={active} eventsOpen={eventsOpen} onToggleEvents={() => setEventsOpen((v) => !v)} onShowEvents={() => setEventsOpen(true)} sidebarOpen={sidebarOpen} onToggleSidebar={() => setSidebarOpen((v) => !v)} unread={unread} onOpenSettings={() => setSettingsOpen(true)} />
       <div style={{ flex: 1, display: "flex", minHeight: 0 }}>
         {sidebarOpen && <Sidebar groups={groups} workspaces={workspaces} activeId={activeId} onSelect={selectWorkspace} onNew={() => setWizard(true)} onDelete={setDeleteTarget} health={health} connected={connected} />}
         <div style={{ flex: 1, display: "flex", flexDirection: "column", minWidth: 0 }}>
@@ -168,6 +170,7 @@ export function App() {
           />
         )}
       </div>
+      {settingsOpen && config && <Settings config={config} health={health} onClose={() => setSettingsOpen(false)} />}
       {wizard && <Wizard onDone={(id) => { setWizard(false); setActiveId(id); void refresh(); }} onCancel={() => setWizard(false)} />}
       {deleteTarget && (
         <ConfirmDelete
diff --git a/app/src/Settings.tsx b/app/src/Settings.tsx
new file mode 100644
index 0000000..7d48945
--- /dev/null
+++ b/app/src/Settings.tsx
@@ -0,0 +1,60 @@
+import { useEffect, useRef } from "react";
+import { COLORS, FONT } from "./theme";
+import { setConfig } from "./socketBridge";
+import type { ConfigView, DaemonHealth } from "./socketBridge";
+
+const FONTS = ["JetBrains Mono", "Menlo", "Monaco", "SF Mono", "Fira Code", "Cascadia Code"];
+const ACCENTS: { id: string; hex: string }[] = [
+  { id: "blue", hex: "#4C8DFF" }, { id: "teal", hex: "#34D3C2" }, { id: "purple", hex: "#9B7BFF" },
+  { id: "green", hex: "#3FB950" }, { id: "orange", hex: "#F2934B" },
+];
+
+export function Settings({ config, health, onClose }: { config: ConfigView; health: DaemonHealth | null; onClose: () => void }) {
+  const ref = useRef<HTMLDivElement>(null);
+  useEffect(() => { ref.current?.focus(); }, []);
+  return (
+    <div onMouseDown={onClose} style={{ position: "fixed", inset: 0, zIndex: 2000, background: "#000A", display: "flex", alignItems: "center", justifyContent: "center" }}>
+      <div ref={ref} tabIndex={-1} onMouseDown={(e) => e.stopPropagation()} onKeyDown={(e) => { e.stopPropagation(); if (e.key === "Escape") onClose(); }}
+        style={{ width: 520, maxHeight: "80vh", overflowY: "auto", background: COLORS.bgApp, border: `1px solid ${COLORS.borderStrong}`, borderRadius: 14, padding: 24, color: COLORS.textPrimary, fontFamily: FONT.ui }}>
+        <div style={{ fontWeight: 700, fontSize: 16, marginBottom: 16 }}>Settings</div>
+
+        <div style={{ fontSize: 12, color: COLORS.textSecondary, marginBottom: 6 }}>Terminal font</div>
+        <select value={config.font_family} onChange={(e) => void setConfig({ font_family: e.target.value })}
+          style={{ width: "100%", padding: 8, marginBottom: 10, background: COLORS.bgPanel, color: COLORS.textPrimary, border: `1px solid ${COLORS.borderStrong}`, borderRadius: 8 }}>
+          {FONTS.map((f) => <option key={f} value={f}>{f}</option>)}
+        </select>
+        <div style={{ display: "flex", alignItems: "center", gap: 10, marginBottom: 18 }}>
+          <span style={{ fontSize: 12, color: COLORS.textSecondary }}>Size {config.font_size}</span>
+          <input type="range" min={10} max={20} value={config.font_size} onChange={(e) => void setConfig({ font_size: Number(e.target.value) })} style={{ flex: 1 }} />
+        </div>
+
+        <div style={{ fontSize: 12, color: COLORS.textSecondary, marginBottom: 6 }}>Theme</div>
+        <div style={{ display: "flex", gap: 8, marginBottom: 12 }}>
+          {(["dark", "light"] as const).map((t) => (
+            <button key={t} onClick={() => void setConfig({ theme: t })}
+              style={{ flex: 1, padding: "8px 0", borderRadius: 8, fontSize: 13, textTransform: "capitalize",
+                background: config.theme === t ? COLORS.accent : COLORS.bgElevated, color: config.theme === t ? "#fff" : COLORS.textPrimary,
+                border: `1px solid ${COLORS.borderStrong}` }}>{t}</button>
+          ))}
+        </div>
+        <div style={{ fontSize: 12, color: COLORS.textSecondary, marginBottom: 6 }}>Accent</div>
+        <div style={{ display: "flex", gap: 10, marginBottom: 18 }}>
+          {ACCENTS.map((a) => (
+            <button key={a.id} onClick={() => void setConfig({ accent: a.id })} aria-label={a.id}
+              style={{ width: 26, height: 26, borderRadius: "50%", background: a.hex, cursor: "pointer",
+                border: config.accent === a.id ? `2px solid ${COLORS.textPrimary}` : "2px solid transparent" }} />
+          ))}
+        </div>
+
+        <div style={{ fontSize: 12, color: COLORS.textSecondary, marginBottom: 6 }}>Default shell (empty = auto)</div>
+        <input defaultValue={config.default_shell} onBlur={(e) => void setConfig({ default_shell: e.target.value })}
+          style={{ width: "100%", padding: 8, marginBottom: 18, background: COLORS.bgPanel, color: COLORS.textPrimary, border: `1px solid ${COLORS.borderStrong}`, borderRadius: 8 }} />
+
+        <DaemonSection health={health} />
+      </div>
+    </div>
+  );
+}
+
+// Placeholder — fleshed out in Task 11. Keep the signature stable.
+function DaemonSection(_props: { health: DaemonHealth | null }) { return null; }
diff --git a/app/src/TopBar.tsx b/app/src/TopBar.tsx
index df90abc..fbff10c 100644
--- a/app/src/TopBar.tsx
+++ b/app/src/TopBar.tsx
@@ -29,7 +29,7 @@ function IconBtn({ icon, onClick, active, title }: { icon: React.ReactNode; onCl
 }
 
 export function TopBar({
-  active, eventsOpen, onToggleEvents, onShowEvents, sidebarOpen, onToggleSidebar, unread,
+  active, eventsOpen, onToggleEvents, onShowEvents, sidebarOpen, onToggleSidebar, unread, onOpenSettings,
 }: {
   active: WorkspaceView | null;
   eventsOpen: boolean;
@@ -38,6 +38,7 @@ export function TopBar({
   sidebarOpen: boolean;
   onToggleSidebar: () => void;
   unread: number;
+  onOpenSettings: () => void;
 }) {
   return (
     <div
@@ -85,7 +86,7 @@ export function TopBar({
           )}
         </div>
         <IconBtn icon={<PanelRight size={15} />} onClick={onToggleEvents} active={eventsOpen} title="Toggle Event Center" />
-        <IconBtn icon={<Settings size={16} />} title="Settings (mock)" />
+        <IconBtn icon={<Settings size={16} />} onClick={onOpenSettings} title="Settings" />
         <span style={{ width: 1, height: 18, background: COLORS.borderStrong, margin: "0 2px" }} />
         <button
           title="Account (mock)"