diff --git a/src/components/DetailPanel.tsx b/src/components/DetailPanel.tsx
index 0b833bb..3b25973 100644
--- a/src/components/DetailPanel.tsx
+++ b/src/components/DetailPanel.tsx
@@ -19,7 +19,7 @@ export function Field({ label, value }: { label: string; value: ReactNode }) {
 }
 
 // Minimize/expand toggle for the mobile overlay only; at md+ the panel is a sidebar so it's hidden.
-function MinimizeButton({ collapsed, onToggle }: { collapsed: boolean; onToggle: () => void }) {
+export function MinimizeButton({ collapsed, onToggle }: { collapsed: boolean; onToggle: () => void }) {
   return (
     <button
       type="button"
diff --git a/src/features/observers/ObserverPage.tsx b/src/features/observers/ObserverPage.tsx
index 1e38d71..1944195 100644
--- a/src/features/observers/ObserverPage.tsx
+++ b/src/features/observers/ObserverPage.tsx
@@ -3,7 +3,9 @@ import { useSearchParams } from "react-router-dom";
 import { useQuery } from "@tanstack/react-query";
 import { useTranslation } from "react-i18next";
 import { getBrokers } from "../../api/client";
+import { CloseButton } from "../../components/CloseButton";
 import { CopyButton } from "../../components/CopyButton";
+import { MinimizeButton } from "../../components/DetailPanel";
 import { EmptyState } from "../../components/EmptyState";
 import { ACTION_BUTTON_CLASS } from "../../components/action-button";
 import { useScopes } from "../../hooks/useScopes";
@@ -17,8 +19,6 @@ import { Segmented } from "../stats/Segmented";
 import type { WsManager } from "../../api/ws-manager";
 const ObserverTab = lazy(() => import("../stats/ObserverTab").then(m => ({ default: m.ObserverTab })));
 
-const NAV_CHIP = "inline-flex items-center gap-1.5 rounded-sm border border-border bg-bg-raised px-2 py-0.5 font-mono text-[11px] text-text-normal transition-colors hover:border-text-dim hover:text-text-bright";
-
 export function ObserverPage({ wsManager }: { wsManager: WsManager }) {
   const [params, setParams] = useSearchParams();
   const { t } = useTranslation();
@@ -37,6 +37,7 @@ export function ObserverPage({ wsManager }: { wsManager: WsManager }) {
   const [type, setType] = useState("");
   const [broker, setBroker] = useState("");
   const [scope, setScope] = useState("");
+  const [minimized, setMinimized] = useState(false);
   const directory = useObserverDirectory(wsManager, broker);
   const { data: brokers } = useQuery({ queryKey: ["brokers"], queryFn: getBrokers, staleTime: 60_000 });
   const scopeOptions = useScopes(scope);
@@ -45,7 +46,7 @@ export function ObserverPage({ wsManager }: { wsManager: WsManager }) {
   const share = new URL(window.location.pathname, window.location.origin); share.search = params.toString();
   if (id) share.searchParams.set("range", range);
   if (comparing && until != null) share.searchParams.set("compareUntil", String(until));
-  const select = (observer: string | null) => setParams(observerDestination(params, observer, range));
+  const select = (observer: string | null) => { setMinimized(false); setParams(observerDestination(params, observer, range)); };
   const compare = (observer: string) => {
     // eslint-disable-next-line react-hooks/purity -- Capture time when the user invokes this event callback.
     const clickedAt = Date.now();
@@ -78,17 +79,21 @@ export function ObserverPage({ wsManager }: { wsManager: WsManager }) {
           <Segmented ariaLabel={t("observerPage.range")} size="sm" value={range} options={[{ value: "24h", label: t("stats.ranges.24h") }, { value: "7d", label: t("stats.ranges.7d") }, { value: "30d", label: t("stats.ranges.30d") }]} onChange={v => setParams(observerDestination(params, id, observerRange(v)))} />
         </span>}
     />
-    <div className="flex min-h-0 min-w-0 flex-1">
-      {/* below md the list and the dashboard take turns */}
-      <div className={`${id ? "hidden md:flex" : "flex"} min-h-0 w-full shrink-0 flex-col p-4 md:w-[260px] md:pr-0`}>
+    <div className="relative flex min-h-0 min-w-0 flex-1">
+      <div className="flex min-h-0 w-full shrink-0 flex-col p-4 md:w-[260px] md:pr-0">
         <ObserverSidebar observers={observers} filtered={Boolean(search || status || type || broker || scope)} isPending={directory.isPending} isError={directory.isError}
           onRetry={() => void directory.refetch()} range={range} selectedId={id} onSelect={select} />
       </div>
-      {id ? <div className="flex min-h-0 min-w-0 flex-1 flex-col">
-        <div className="px-4 pt-3 md:hidden">
-          <button type="button" aria-label={t("observerPage.back")} onClick={() => select(null)} className={NAV_CHIP}><span aria-hidden>‹</span>{t("observerPage.directory")}</button>
+      {/* below md the dashboard overlays the list, like the node detail panel */}
+      {id ? <div className={`${minimized ? "absolute inset-x-0 bottom-0" : "absolute inset-0"} z-30 flex min-h-0 min-w-0 flex-col bg-bg-base md:static md:z-auto md:flex-1`}>
+        <div className="flex shrink-0 items-center justify-between border-b border-border-subtle bg-bg-surface px-3 py-2 md:hidden">
+          <span className="font-mono text-[13px] font-medium uppercase tracking-wider text-text-dim">{t("observerPage.detail")}</span>
+          <div className="-mr-1 flex items-center gap-0.5">
+            <MinimizeButton collapsed={minimized} onToggle={() => setMinimized(v => !v)} />
+            <CloseButton onClose={() => select(null)} label={t("observerPage.back")} />
+          </div>
         </div>
-        <div className="min-h-0 flex-1 overflow-auto">
+        <div className={`min-h-0 flex-1 overflow-auto ${minimized ? "hidden md:block" : ""}`}>
         <Suspense fallback={<p role="status" className="p-4">{t("common.loading")}</p>}>
           <ObserverTab range={range} selectedObserverId={id} onSelectObserver={select} wsManager={wsManager} actions={<>
             <CopyButton value={share.toString()} label={t("observerPage.copyLinkShort")} copiedLabel={t("observerPage.copied")} ariaLabel={t("observerPage.copyLink")} className="justify-center py-1" />
diff --git a/src/features/observers/ObserverSidebar.tsx b/src/features/observers/ObserverSidebar.tsx
index 1d59cbf..c6077cd 100644
--- a/src/features/observers/ObserverSidebar.tsx
+++ b/src/features/observers/ObserverSidebar.tsx
@@ -61,7 +61,7 @@ export function ObserverSidebar({ observers, filtered, isPending, isError, onRet
                     active ? "border-primary bg-primary/10" : "border-transparent hover:bg-text-normal/3"
                   }`}
                 >
-                  {count != null && <div className="absolute bottom-0 left-0 h-0.5 bg-secondary/40" style={{ width: `${(count / max) * 100}%` }} aria-hidden />}
+                  {count != null && <div className="absolute inset-y-0 left-0 bg-secondary/15" style={{ width: `${(count / max) * 100}%` }} aria-hidden />}
                   <div className="relative flex items-center gap-2">
                     <span aria-hidden className={`h-1.5 w-1.5 shrink-0 rounded-full ${deriveObserverStatus(o) === "online" ? "bg-green" : "bg-text-dim/30"}`} />
                     <span className={`min-w-0 flex-1 truncate font-mono text-[12px] ${active ? "text-text-bright" : "text-text-normal"}`}>{nameOf(o)}</span>
diff --git a/src/i18n/locales/en.json b/src/i18n/locales/en.json
index 0c8c5dc..45df1cc 100644
--- a/src/i18n/locales/en.json
+++ b/src/i18n/locales/en.json
@@ -258,6 +258,7 @@
     },
     "observerPage": {
       "back": "Back to observers",
+      "detail": "Observer detail",
       "range": "Time range",
       "open": "Open observer dashboard",
       "legacy": "Legacy presence count",
@@ -309,7 +310,6 @@
       "recording": "Loading observer…",
       "hour": "hour",
       "day": "day",
-      "directory": "All observers",
       "sidebarSearch": "Search observers",
       "noMatches": "No matches",
       "none": "No observers",
diff --git a/src/i18n/locales/fr.json b/src/i18n/locales/fr.json
index a919723..1be2ee5 100644
--- a/src/i18n/locales/fr.json
+++ b/src/i18n/locales/fr.json
@@ -262,6 +262,7 @@
     },
     "observerPage": {
       "back": "Retour aux observateurs",
+      "detail": "Détail de l'observateur",
       "range": "Période",
       "open": "Ouvrir le tableau de bord",
       "legacy": "Ancien compteur de présence",
@@ -313,7 +314,6 @@
       "recording": "Chargement de l’observateur…",
       "hour": "heure",
       "day": "jour",
-      "directory": "Tous les observateurs",
       "sidebarSearch": "Rechercher les observateurs",
       "noMatches": "Aucun résultat",
       "none": "Aucun observateur",
diff --git a/tests/features/observers/ObserverPage.test.tsx b/tests/features/observers/ObserverPage.test.tsx
index 6620222..43550de 100644
--- a/tests/features/observers/ObserverPage.test.tsx
+++ b/tests/features/observers/ObserverPage.test.tsx
@@ -116,15 +116,26 @@ describe("Observer destination", () => {
     expect(within(header).getByRole("button", { name: "Copy observer link" })).toHaveTextContent("Copy link");
     expect(screen.getAllByRole("button", { name: "Compare with…" })).toHaveLength(1);
   });
-  it("only offers a return to the list on mobile, where the list is hidden", async () => {
+  it("closes the mobile overlay from its header, back to the list", async () => {
     view("?tab=Observers&observer=observer-a&range=7d");
     await screen.findByRole("heading");
-    const back = screen.getByRole("button", { name: /Back to observers/ });
-    expect(back.closest(".md\\:hidden")).not.toBeNull();
-    fireEvent.click(back);
+    const header = screen.getByText("Observer detail").parentElement!;
+    expect(header).toHaveClass("md:hidden");
+    fireEvent.click(within(header).getByRole("button", { name: "Back to observers" }));
     expect(screen.queryByRole("heading")).not.toBeInTheDocument();
     expect(screen.getByRole("status").textContent).not.toContain("observer=");
   });
+  it("minimizes the mobile overlay over the list and expands for the next pick", async () => {
+    view("?tab=Observers&observer=observer-a&range=7d");
+    const body = () => screen.getByRole("heading").closest(".overflow-auto")!;
+    await screen.findByRole("heading");
+    expect(list().getAllByRole("button")).toHaveLength(2);
+    fireEvent.click(screen.getByRole("button", { name: "Minimize detail panel" }));
+    expect(body()).toHaveClass("hidden");
+    fireEvent.click(list().getByText("Basement B"));
+    expect(await screen.findByRole("heading")).toHaveTextContent("observer-b");
+    expect(body()).not.toHaveClass("hidden");
+  });
 });
 
 it("anchors a new comparison at the click time and accepts Refresh across an hour boundary", async () => {