diff --git a/client/src/app/App.tsx b/client/src/app/App.tsx
index a6bd55e..9b5ac68 100644
--- a/client/src/app/App.tsx
+++ b/client/src/app/App.tsx
@@ -1,12 +1,33 @@
 import { BrowserRouter, Route, Routes } from 'react-router-dom';
 import { VisitProvider } from '../features/visits/context/VisitProvider';
+import { useCallback, useState } from 'react';
 import { PrimaryLayout } from '../components/layout/PrimaryLayout';
 import { VisitSidebar } from '../components/layout/VisitSidebar';
 import { TravelMap } from '../features/map/TravelMap';
 import { VisitModal } from '../components/overlay/VisitModal';
+import { useVisitModalStore } from '../state/useVisitModalStore';
 
 function HomePage() {
-  return <PrimaryLayout sidebar={<VisitSidebar />} content={<TravelMap />} />;
+  const openForCreate = useVisitModalStore((state) => state.openForCreate);
+  const [isSidebarOpen, setIsSidebarOpen] = useState(true);
+
+  const handleSidebarToggle = useCallback(
+    (isOpen: boolean) => {
+      setIsSidebarOpen(isOpen);
+      if (!isOpen) {
+        useVisitModalStore.getState().close();
+      }
+    },
+    []
+  );
+
+  return (
+    <PrimaryLayout
+      sidebar={<VisitSidebar />}
+      content={<TravelMap onTriggerCreate={openForCreate} sidebarOpen={isSidebarOpen} />}
+      onSidebarToggle={handleSidebarToggle}
+    />
+  );
 }
 
 export function App() {
diff --git a/client/src/components/layout/PrimaryLayout.tsx b/client/src/components/layout/PrimaryLayout.tsx
index 0d20068..0b899ab 100644
--- a/client/src/components/layout/PrimaryLayout.tsx
+++ b/client/src/components/layout/PrimaryLayout.tsx
@@ -1,22 +1,40 @@
-import type { ReactNode } from 'react';
+import { useEffect, useState, type ReactNode } from 'react';
 import { useTranslation } from 'react-i18next';
 import { LanguageSwitcher } from './LanguageSwitcher';
 
 interface PrimaryLayoutProps {
   sidebar: ReactNode;
   content: ReactNode;
+  onSidebarToggle?: (isOpen: boolean) => void;
 }
 
-export function PrimaryLayout({ sidebar, content }: PrimaryLayoutProps) {
+export function PrimaryLayout({ sidebar, content, onSidebarToggle }: PrimaryLayoutProps) {
   const { t } = useTranslation();
+  const [isSidebarOpen, setIsSidebarOpen] = useState(true);
+
+  useEffect(() => {
+    onSidebarToggle?.(isSidebarOpen);
+  }, [isSidebarOpen, onSidebarToggle]);
 
   return (
     <div className="flex h-screen flex-col">
       <header className="border-b border-slate-200 bg-white">
         <div className="mx-auto flex max-w-6xl items-center justify-between px-6 py-4">
-          <div>
-            <h1 className="text-2xl font-bold">{t('common.appName')}</h1>
-            <p className="text-sm text-slate-500">{t('common.tagline')}</p>
+          <div className="flex items-center gap-3">
+            <button
+              type="button"
+              aria-label={t(isSidebarOpen ? 'sidebar.toggleClose' : 'sidebar.toggleOpen')}
+              aria-controls="visit-sidebar"
+              aria-expanded={isSidebarOpen}
+              className="rounded bg-slate-100 p-2 text-slate-600 transition hover:bg-slate-200 focus:outline-none focus:ring-2 focus:ring-primary"
+              onClick={() => setIsSidebarOpen((prev) => !prev)}
+            >
+              <span className="block text-xl leading-none">{isSidebarOpen ? '⟨' : '☰'}</span>
+            </button>
+            <div>
+              <h1 className="text-2xl font-bold">{t('common.appName')}</h1>
+              <p className="text-sm text-slate-500">{t('common.tagline')}</p>
+            </div>
           </div>
           <div className="flex items-center gap-4">
             <nav className="flex items-center gap-3 text-sm text-slate-500">
@@ -32,9 +50,17 @@ export function PrimaryLayout({ sidebar, content }: PrimaryLayoutProps) {
         </div>
       </header>
       <main className="flex flex-1 overflow-hidden">
-        <section className="w-full max-w-lg border-r border-slate-200">
-          {sidebar}
-        </section>
+        <aside
+          id="visit-sidebar"
+          aria-hidden={!isSidebarOpen}
+          className={`flex-shrink-0 min-w-0 overflow-hidden transition-[flex-basis,max-width] duration-300 ease-in-out ${
+            isSidebarOpen
+              ? 'basis-[25%] max-w-[25%] border-r border-slate-200'
+              : 'pointer-events-none basis-0 max-w-0'
+          }`}
+        >
+          {isSidebarOpen ? <div className="h-full">{sidebar}</div> : null}
+        </aside>
         <section className="flex-1">{content}</section>
       </main>
     </div>
diff --git a/client/src/features/map/TravelMap.tsx b/client/src/features/map/TravelMap.tsx
index 248b907..0a6d26d 100644
--- a/client/src/features/map/TravelMap.tsx
+++ b/client/src/features/map/TravelMap.tsx
@@ -1,11 +1,13 @@
 import { MapContainer, Marker, Popup, TileLayer, useMapEvents } from 'react-leaflet';
 import 'leaflet/dist/leaflet.css';
-import { useEffect } from 'react';
+import { useEffect, useRef } from 'react';
 import type { LeafletMouseEvent } from 'leaflet';
 import { ensureLeafletConfig } from './leafletConfig';
 import { useVisitModalStore } from '../../state/useVisitModalStore';
 import { useVisitsQuery } from '../visits/hooks/useVisitQueries';
 import { useTranslation } from 'react-i18next';
+import { useResizeMap } from '../visits/hooks/useResizeMap';
+import type { Map as LeafletMap } from 'leaflet';
 
 const INITIAL_POSITION: [number, number] = [20, 0];
 const INITIAL_ZOOM = 2;
@@ -23,7 +25,12 @@ function MapEvents() {
   return null;
 }
 
-export function TravelMap() {
+interface TravelMapProps {
+  onTriggerCreate?: (location?: { lat: number; lng: number }) => void;
+  sidebarOpen?: boolean;
+}
+
+export function TravelMap({ onTriggerCreate, sidebarOpen = true }: TravelMapProps) {
   useEffect(() => {
     ensureLeafletConfig();
   }, []);
@@ -32,10 +39,21 @@ export function TravelMap() {
 
   const openForCreate = useVisitModalStore((state) => state.openForCreate);
   const { t } = useTranslation();
+  const mapRef = useRef<LeafletMap | null>(null);
+  useResizeMap(mapRef, [sidebarOpen]);
 
   return (
     <div className="relative h-full w-full">
-      <MapContainer className="h-full w-full z-0" center={INITIAL_POSITION} zoom={INITIAL_ZOOM} scrollWheelZoom>
+      <MapContainer
+        whenCreated={(mapInstance) => {
+          mapRef.current = mapInstance;
+          mapInstance.invalidateSize();
+        }}
+        className="h-full w-full z-0"
+        center={INITIAL_POSITION}
+        zoom={INITIAL_ZOOM}
+        scrollWheelZoom
+      >
         <TileLayer
           attribution='\u00a9 <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a>'
           url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
@@ -60,7 +78,7 @@ export function TravelMap() {
         type="button"
         aria-label={t('sidebar.add')}
         className="absolute bottom-5 right-5 z-10 flex h-12 w-12 items-center justify-center rounded-full bg-primary text-2xl font-bold text-white shadow-lg transition hover:bg-primary/90"
-        onClick={() => openForCreate()}
+        onClick={() => (onTriggerCreate ? onTriggerCreate() : openForCreate())}
       >
         +
       </button>
diff --git a/client/src/features/visits/hooks/useResizeMap.ts b/client/src/features/visits/hooks/useResizeMap.ts
new file mode 100644
index 0000000..ac326f7
--- /dev/null
+++ b/client/src/features/visits/hooks/useResizeMap.ts
@@ -0,0 +1,13 @@
+import { useEffect, type DependencyList } from 'react';
+import type { Map as LeafletMap } from 'leaflet';
+import { useVisitModalStore } from '../../../state/useVisitModalStore';
+
+export function useResizeMap(mapRef: React.RefObject<LeafletMap | null>, deps: DependencyList = []) {
+  const isModalOpen = useVisitModalStore((state) => state.isOpen);
+
+  useEffect(() => {
+    const map = mapRef.current;
+    if (!map) return;
+    setTimeout(() => map.invalidateSize(), 0);
+  }, [mapRef, isModalOpen, ...deps]);
+}
diff --git a/client/src/locales/en/translation.json b/client/src/locales/en/translation.json
index be0cb18..8e8e70f 100644
--- a/client/src/locales/en/translation.json
+++ b/client/src/locales/en/translation.json
@@ -18,7 +18,9 @@
     "add": "Add Visit",
     "drawerTitleCreate": "Add Visit",
     "drawerTitleEdit": "Edit Visit",
-    "close": "Close"
+    "close": "Close",
+    "toggleOpen": "Show sidebar",
+    "toggleClose": "Hide sidebar"
   },
   "summary": {
     "title": "Stats",
diff --git a/client/src/locales/zh-Hant/translation.json b/client/src/locales/zh-Hant/translation.json
index 258855f..813f953 100644
--- a/client/src/locales/zh-Hant/translation.json
+++ b/client/src/locales/zh-Hant/translation.json
@@ -18,7 +18,9 @@
     "add": "新增足跡",
     "drawerTitleCreate": "新增足跡",
     "drawerTitleEdit": "編輯足跡",
-    "close": "關閉"
+    "close": "關閉",
+    "toggleOpen": "展開側邊欄",
+    "toggleClose": "收合側邊欄"
   },
   "summary": {
     "title": "統計",