diff --git a/apps/readest-app/src/__tests__/components/Dropdown.test.tsx b/apps/readest-app/src/__tests__/components/Dropdown.test.tsx
index f783547f..b46528e8 100644
--- a/apps/readest-app/src/__tests__/components/Dropdown.test.tsx
+++ b/apps/readest-app/src/__tests__/components/Dropdown.test.tsx
@@ -29,6 +29,18 @@ const renderDropdown = () =>
     </DropdownProvider>,
   );
 
+const renderTwoDropdowns = () =>
+  render(
+    <DropdownProvider>
+      <Dropdown label='First Menu' toggleButton={<span>First</span>} showTooltip={false}>
+        <div>First content</div>
+      </Dropdown>
+      <Dropdown label='Second Menu' toggleButton={<span>Second</span>} showTooltip={false}>
+        <div>Second content</div>
+      </Dropdown>
+    </DropdownProvider>,
+  );
+
 describe('Dropdown keyboard activation', () => {
   it('opens when Enter is pressed on the toggle button', () => {
     renderDropdown();
@@ -91,4 +103,29 @@ describe('Dropdown keyboard activation', () => {
       window.removeEventListener('keydown', onWindowKeyDown);
     }
   });
+
+  it('closes when the pointer is pressed outside', () => {
+    renderDropdown();
+    const toggle = screen.getByRole('button', { name: 'Test Menu' });
+
+    fireEvent.click(toggle);
+    expect(toggle.getAttribute('aria-expanded')).toBe('true');
+
+    fireEvent.pointerDown(document.body);
+    expect(toggle.getAttribute('aria-expanded')).toBe('false');
+  });
+
+  it('switches directly to another dropdown on the first click', () => {
+    renderTwoDropdowns();
+    const first = screen.getByRole('button', { name: 'First Menu' });
+    const second = screen.getByRole('button', { name: 'Second Menu' });
+
+    fireEvent.click(first);
+    expect(first.getAttribute('aria-expanded')).toBe('true');
+
+    fireEvent.pointerDown(second);
+    fireEvent.click(second);
+    expect(first.getAttribute('aria-expanded')).toBe('false');
+    expect(second.getAttribute('aria-expanded')).toBe('true');
+  });
 });
diff --git a/apps/readest-app/src/app/library/components/BookItem.tsx b/apps/readest-app/src/app/library/components/BookItem.tsx
index 0d4cda52..8345631c 100644
--- a/apps/readest-app/src/app/library/components/BookItem.tsx
+++ b/apps/readest-app/src/app/library/components/BookItem.tsx
@@ -126,7 +126,7 @@ const BookItem: React.FC<BookItemProps> = ({
       role='none'
       className={clsx(
         'book-item flex',
-        mode === 'grid' && 'h-full flex-col justify-end',
+        mode === 'grid' && 'h-full w-full flex-col justify-end',
         mode === 'list' && 'min-h-28 flex-row gap-4 overflow-hidden',
         mode === 'list' ? 'library-list-item' : 'library-grid-item',
         appService?.hasContextMenu ? 'cursor-pointer' : '',
diff --git a/apps/readest-app/src/app/library/components/Bookshelf.tsx b/apps/readest-app/src/app/library/components/Bookshelf.tsx
index c2f35e14..3e431529 100644
--- a/apps/readest-app/src/app/library/components/Bookshelf.tsx
+++ b/apps/readest-app/src/app/library/components/Bookshelf.tsx
@@ -90,6 +90,7 @@ interface BookshelfProps {
   handlePushLibrary: () => Promise<void>;
   booksTransferProgress: { [key: string]: number | null };
   categoryFilter?: LibraryCategoryFilter;
+  sidebarVisible?: boolean;
 }
 
 /**
@@ -100,6 +101,7 @@ interface BookshelfProps {
 type BookshelfListContext = {
   autoColumns: boolean;
   fixedColumns: number;
+  sidebarVisible: boolean;
   /**
    * The recently-read shelf, rendered in the Virtuoso header so it scrolls with
    * the shelf content (not sticky). `null` when hidden. Passed through context
@@ -109,9 +111,12 @@ type BookshelfListContext = {
   recentShelfHeader: React.ReactNode;
 };
 
-const BOOKSHELF_GRID_CLASSES =
-  'bookshelf-items transform-wrapper grid gap-x-4 px-4 sm:gap-x-0 sm:px-2 ' +
+const BOOKSHELF_GRID_BASE_CLASSES =
+  'bookshelf-items transform-wrapper grid gap-x-4 px-4 sm:gap-x-0 sm:px-2';
+const BOOKSHELF_GRID_DEFAULT_COLUMNS =
   'grid-cols-3 sm:grid-cols-4 md:grid-cols-6 xl:grid-cols-8 2xl:grid-cols-12';
+const BOOKSHELF_GRID_SIDEBAR_COLUMNS =
+  'grid-cols-3 sm:grid-cols-4 md:grid-cols-3 lg:grid-cols-4 xl:grid-cols-5 2xl:grid-cols-8';
 
 const BOOKSHELF_LIST_CLASSES = 'bookshelf-items transform-wrapper flex flex-col';
 
@@ -122,7 +127,11 @@ const BookshelfGridList: GridComponents<BookshelfListContext>['List'] = React.fo
   <div
     ref={ref}
     data-testid={testId}
-    className={clsx(BOOKSHELF_GRID_CLASSES, className)}
+    className={clsx(
+      BOOKSHELF_GRID_BASE_CLASSES,
+      context?.sidebarVisible ? BOOKSHELF_GRID_SIDEBAR_COLUMNS : BOOKSHELF_GRID_DEFAULT_COLUMNS,
+      className,
+    )}
     style={{
       ...style,
       gridTemplateColumns:
@@ -178,6 +187,7 @@ const Bookshelf: React.FC<BookshelfProps> = ({
   handlePushLibrary,
   booksTransferProgress,
   categoryFilter = 'all',
+  sidebarVisible = false,
 }) => {
   const _ = useTranslation();
   const router = useRouter();
@@ -849,6 +859,7 @@ const Bookshelf: React.FC<BookshelfProps> = ({
           coverFit={coverFit as LibraryCoverFitType}
           autoColumns={settings.libraryAutoColumns}
           fixedColumns={settings.libraryColumns}
+          sidebarVisible={sidebarVisible}
           onOpenBook={openRecentBook}
           handleBookUpload={handleBookUpload}
           handleBookDownload={handleBookDownload}
@@ -861,6 +872,7 @@ const Bookshelf: React.FC<BookshelfProps> = ({
       coverFit,
       settings.libraryAutoColumns,
       settings.libraryColumns,
+      sidebarVisible,
       openRecentBook,
       handleBookUpload,
       handleBookDownload,
@@ -872,9 +884,10 @@ const Bookshelf: React.FC<BookshelfProps> = ({
     () => ({
       autoColumns: settings.libraryAutoColumns,
       fixedColumns: settings.libraryColumns,
+      sidebarVisible,
       recentShelfHeader,
     }),
-    [settings.libraryAutoColumns, settings.libraryColumns, recentShelfHeader],
+    [settings.libraryAutoColumns, settings.libraryColumns, sidebarVisible, recentShelfHeader],
   );
 
   const renderBookshelfItem = useCallback(
diff --git a/apps/readest-app/src/app/library/components/GroupItem.tsx b/apps/readest-app/src/app/library/components/GroupItem.tsx
index e3f282a3..1722fb6f 100644
--- a/apps/readest-app/src/app/library/components/GroupItem.tsx
+++ b/apps/readest-app/src/app/library/components/GroupItem.tsx
@@ -22,6 +22,7 @@ const GroupItem: React.FC<GroupItemProps> = ({ mode, group, isSelectMode, groupS
   const scrollContainerRef = useRef<HTMLDivElement>(null);
   const [showLeftArrow, setShowLeftArrow] = useState(false);
   const [showRightArrow, setShowRightArrow] = useState(false);
+  const isSingleBookGrid = mode === 'grid' && group.books.length === 1;
 
   const checkScrollArrows = () => {
     if (mode === 'list' && scrollContainerRef.current) {
@@ -115,7 +116,10 @@ const GroupItem: React.FC<GroupItemProps> = ({ mode, group, isSelectMode, groupS
           <div
             ref={mode === 'list' ? scrollContainerRef : undefined}
             className={clsx(
-              mode === 'grid' && 'grid w-full grid-cols-2 grid-rows-2 gap-1 overflow-hidden',
+              mode === 'grid' &&
+                (isSingleBookGrid
+                  ? 'flex w-full overflow-hidden'
+                  : 'grid w-full grid-cols-2 grid-rows-2 gap-1 overflow-hidden'),
               mode === 'list' && 'flex h-28 gap-2 overflow-x-auto overflow-y-hidden',
               mode === 'list' ? 'library-list-item' : 'library-grid-item',
             )}
@@ -137,7 +141,7 @@ const GroupItem: React.FC<GroupItemProps> = ({ mode, group, isSelectMode, groupS
                 key={book.hash}
                 className={clsx(
                   'relative aspect-[28/41] h-full',
-                  mode === 'grid' && 'w-full',
+                  mode === 'grid' && (isSingleBookGrid ? 'mx-auto' : 'w-full'),
                   mode === 'list' && 'flex-shrink-0',
                 )}
               >
diff --git a/apps/readest-app/src/app/library/components/ImportMenu.tsx b/apps/readest-app/src/app/library/components/ImportMenu.tsx
index 041288bc..7c57fbaa 100644
--- a/apps/readest-app/src/app/library/components/ImportMenu.tsx
+++ b/apps/readest-app/src/app/library/components/ImportMenu.tsx
@@ -8,6 +8,7 @@ import Menu from '@/components/Menu';
 
 interface ImportMenuProps {
   setIsDropdownOpen?: (open: boolean) => void;
+  menuClassName?: string;
   onImportBooksFromFiles: () => void;
   onImportBooksFromDirectory?: () => void;
   onImportBookFromUrl?: () => void;
@@ -16,6 +17,7 @@ interface ImportMenuProps {
 
 const ImportMenu: React.FC<ImportMenuProps> = ({
   setIsDropdownOpen,
+  menuClassName,
   onImportBooksFromFiles,
   onImportBooksFromDirectory,
   onImportBookFromUrl,
@@ -46,7 +48,10 @@ const ImportMenu: React.FC<ImportMenuProps> = ({
 
   return (
     <Menu
-      className={clsx('dropdown-content bg-base-100 rounded-box !relative z-[1] mt-3 p-2 shadow')}
+      className={clsx(
+        'dropdown-content bg-base-100 rounded-box !relative z-[1] mt-3 p-2 shadow',
+        menuClassName,
+      )}
       onCancel={() => setIsDropdownOpen?.(false)}
     >
       <MenuItem
diff --git a/apps/readest-app/src/app/library/components/LibraryHeader.tsx b/apps/readest-app/src/app/library/components/LibraryHeader.tsx
index f9af5d78..69bcdf00 100644
--- a/apps/readest-app/src/app/library/components/LibraryHeader.tsx
+++ b/apps/readest-app/src/app/library/components/LibraryHeader.tsx
@@ -14,6 +14,7 @@ import { useTranslation } from '@/hooks/useTranslation';
 import { useLibraryStore } from '@/store/libraryStore';
 import { useTrafficLight } from '@/hooks/useTrafficLight';
 import { useResponsiveSize } from '@/hooks/useResponsiveSize';
+import { useIsMobileViewport } from '@/hooks/useIsMobileViewport';
 import { debounce } from '@/utils/debounce';
 import useShortcuts from '@/hooks/useShortcuts';
 import WindowButtons from '@/components/WindowButtons';
@@ -33,6 +34,7 @@ interface LibraryHeaderProps {
   onToggleSelectMode: () => void;
   onSelectAll: () => void;
   onDeselectAll: () => void;
+  onToggleSidebar: () => void;
 }
 
 const LibraryHeader: React.FC<LibraryHeaderProps> = ({
@@ -46,6 +48,7 @@ const LibraryHeader: React.FC<LibraryHeaderProps> = ({
   onToggleSelectMode,
   onSelectAll,
   onDeselectAll,
+  onToggleSidebar,
 }) => {
   const _ = useTranslation();
   const router = useRouter();
@@ -59,6 +62,7 @@ const LibraryHeader: React.FC<LibraryHeaderProps> = ({
   const { isTrafficLightVisible } = useTrafficLight(headerRef);
   const iconSize18 = useResponsiveSize(18);
   const { safeAreaInsets: insets } = useThemeStore();
+  const isNarrowViewport = useIsMobileViewport(641);
 
   useShortcuts({
     onToggleSelectMode,
@@ -92,7 +96,7 @@ const LibraryHeader: React.FC<LibraryHeaderProps> = ({
 
   if (!insets) return null;
 
-  const isMobile = appService?.isMobile || window.innerWidth <= 640;
+  const isMobile = appService?.isMobile || isNarrowViewport;
 
   return (
     <div
@@ -109,8 +113,17 @@ const LibraryHeader: React.FC<LibraryHeaderProps> = ({
       }}
     >
       <div className='flex w-full items-center justify-between space-x-6 sm:space-x-12'>
-        <div className='exclude-title-bar-mousedown relative flex w-full items-center pl-4'>
-          <div className='relative flex h-9 w-full items-center sm:h-7'>
+        <div className='exclude-title-bar-mousedown relative flex w-full items-center gap-2 pl-2 sm:pl-4'>
+          <button
+            type='button'
+            className='btn btn-ghost h-8 min-h-8 w-8 shrink-0 p-0'
+            aria-label={_('Toggle Sidebar')}
+            title={_('Toggle Sidebar')}
+            onClick={onToggleSidebar}
+          >
+            <MdOutlineMenu role='none' size={iconSize18} />
+          </button>
+          <div className='relative flex h-9 min-w-0 flex-1 items-center sm:h-7'>
             <span className='text-base-content/50 absolute ps-3'>
               <FaSearch className='h-4 w-4' />
             </span>
diff --git a/apps/readest-app/src/app/library/components/LibrarySidebar.tsx b/apps/readest-app/src/app/library/components/LibrarySidebar.tsx
index 4f02bacd..384f6fb0 100644
--- a/apps/readest-app/src/app/library/components/LibrarySidebar.tsx
+++ b/apps/readest-app/src/app/library/components/LibrarySidebar.tsx
@@ -44,6 +44,8 @@ interface LibrarySidebarProps {
   onImportBookFromUrl?: () => void;
   onOpenCatalogManager: () => void;
   onToggleSelectMode: () => void;
+  onToggleSidebar: () => void;
+  isViewportResolved: boolean;
 }
 
 type CategoryItem = {
@@ -63,6 +65,8 @@ const LibrarySidebar: React.FC<LibrarySidebarProps> = ({
   onImportBookFromUrl,
   onOpenCatalogManager,
   onToggleSelectMode,
+  onToggleSidebar,
+  isViewportResolved,
 }) => {
   const _ = useTranslation();
   const router = useRouter();
@@ -160,13 +164,22 @@ const LibrarySidebar: React.FC<LibrarySidebarProps> = ({
   return (
     <aside
       className={clsx(
-        'library-sidebar bg-base-200/80 border-base-300/70 hidden h-full w-[248px] shrink-0 flex-col border-r md:flex',
+        'library-sidebar bg-base-200/95 border-base-300/70 fixed inset-y-0 start-0 z-50 h-full w-[min(82vw,248px)] shrink-0 flex-col border-r md:relative md:inset-auto md:z-auto md:w-[248px]',
+        isViewportResolved ? 'flex' : 'hidden md:flex',
         'pt-[max(env(safe-area-inset-top),0px)]',
       )}
     >
       <div className='exclude-title-bar-mousedown flex min-h-0 flex-1 flex-col px-3 py-3'>
         <div className='mb-3 flex h-8 items-center gap-2 px-1'>
-          <MdOutlineMenu className='text-base-content/70 h-5 w-5 shrink-0' />
+          <button
+            type='button'
+            className='btn btn-ghost h-7 min-h-7 w-7 shrink-0 p-0'
+            aria-label={_('Toggle Sidebar')}
+            title={_('Toggle Sidebar')}
+            onClick={onToggleSidebar}
+          >
+            <MdOutlineMenu className='text-base-content/70 h-5 w-5' />
+          </button>
           <div className='min-w-0 flex-1 truncate text-sm font-semibold'>Readest</div>
         </div>
 
@@ -268,6 +281,7 @@ const LibrarySidebar: React.FC<LibrarySidebarProps> = ({
           <Dropdown
             label={_('Import Books')}
             className='exclude-title-bar-mousedown dropdown-top dropdown-start'
+            menuClassName='mb-2 mt-0'
             buttonClassName='btn btn-ghost h-8 min-h-8 w-8 p-0'
             toggleButton={<PiPlus role='none' size={iconSize18} />}
           >
@@ -280,7 +294,8 @@ const LibrarySidebar: React.FC<LibrarySidebarProps> = ({
           </Dropdown>
           <Dropdown
             label={_('View Menu')}
-            className='exclude-title-bar-mousedown dropdown-top dropdown-start'
+            className='exclude-title-bar-mousedown dropdown-top dropdown-center'
+            menuClassName='mb-2 mt-0'
             buttonClassName='btn btn-ghost h-8 min-h-8 w-8 p-0'
             toggleButton={<PiDotsThreeCircle role='none' size={iconSize18} />}
           >
@@ -301,7 +316,8 @@ const LibrarySidebar: React.FC<LibrarySidebarProps> = ({
           <div className='flex-1' />
           <Dropdown
             label={_('Settings Menu')}
-            className='exclude-title-bar-mousedown dropdown-top dropdown-start'
+            className='exclude-title-bar-mousedown dropdown-top dropdown-end'
+            menuClassName='mb-2 mt-0'
             buttonClassName='btn btn-ghost h-8 min-h-8 w-8 p-0'
             toggleButton={<PiGear role='none' size={iconSize18} />}
           >
diff --git a/apps/readest-app/src/app/library/components/RecentShelf.tsx b/apps/readest-app/src/app/library/components/RecentShelf.tsx
index d6267dbc..66b0ff46 100644
--- a/apps/readest-app/src/app/library/components/RecentShelf.tsx
+++ b/apps/readest-app/src/app/library/components/RecentShelf.tsx
@@ -19,6 +19,7 @@ interface RecentShelfProps {
   // Mirror the bookshelf grid's column model so covers are the same size.
   autoColumns: boolean;
   fixedColumns: number;
+  sidebarVisible?: boolean;
   onOpenBook: (book: Book) => void;
   handleBookUpload: (book: Book) => void;
   handleBookDownload: (book: Book, options?: { redownload?: boolean; queued?: boolean }) => void;
@@ -110,6 +111,7 @@ const RecentShelf: React.FC<RecentShelfProps> = ({
   coverFit,
   autoColumns,
   fixedColumns,
+  sidebarVisible = false,
   onOpenBook,
   handleBookUpload,
   handleBookDownload,
@@ -121,7 +123,9 @@ const RecentShelf: React.FC<RecentShelfProps> = ({
   // `--rs-gap` mirrors the grid's `gap-x-4 sm:gap-x-0` so the width formula
   // subtracts the right gap at each breakpoint.
   const colsClass = autoColumns
-    ? '[--rs-cols:3] sm:[--rs-cols:4] md:[--rs-cols:6] xl:[--rs-cols:8] 2xl:[--rs-cols:12]'
+    ? sidebarVisible
+      ? '[--rs-cols:3] sm:[--rs-cols:4] md:[--rs-cols:3] lg:[--rs-cols:4] xl:[--rs-cols:5] 2xl:[--rs-cols:8]'
+      : '[--rs-cols:3] sm:[--rs-cols:4] md:[--rs-cols:6] xl:[--rs-cols:8] 2xl:[--rs-cols:12]'
     : '';
   const colsStyle = autoColumns
     ? undefined
@@ -162,7 +166,7 @@ const RecentShelf: React.FC<RecentShelfProps> = ({
     const observer = new ResizeObserver(measure);
     observer.observe(el);
     return () => observer.disconnect();
-  }, [measure, books, autoColumns, fixedColumns, coverFit]);
+  }, [measure, books, autoColumns, fixedColumns, sidebarVisible, coverFit]);
 
   const scrollByPage = (direction: -1 | 1) => {
     const el = scrollerRef.current;
diff --git a/apps/readest-app/src/app/library/components/SettingsMenu.tsx b/apps/readest-app/src/app/library/components/SettingsMenu.tsx
index 17d5b087..78d2d075 100644
--- a/apps/readest-app/src/app/library/components/SettingsMenu.tsx
+++ b/apps/readest-app/src/app/library/components/SettingsMenu.tsx
@@ -47,9 +47,14 @@ import { type AppLockDialogMode, useAppLockStore } from '@/store/appLockStore';
 interface SettingsMenuProps {
   onPullLibrary: (fullRefresh?: boolean, verbose?: boolean) => void;
   setIsDropdownOpen?: (isOpen: boolean) => void;
+  menuClassName?: string;
 }
 
-const SettingsMenu: React.FC<SettingsMenuProps> = ({ onPullLibrary, setIsDropdownOpen }) => {
+const SettingsMenu: React.FC<SettingsMenuProps> = ({
+  onPullLibrary,
+  setIsDropdownOpen,
+  menuClassName,
+}) => {
   const _ = useTranslation();
   const router = useRouter();
   const { envConfig, appService } = useEnv();
@@ -318,6 +323,7 @@ const SettingsMenu: React.FC<SettingsMenuProps> = ({ onPullLibrary, setIsDropdow
       className={clsx(
         'settings-menu dropdown-content no-triangle',
         'z-20 mt-2 max-w-[90vw] shadow-2xl',
+        menuClassName,
       )}
       onCancel={() => setIsDropdownOpen?.(false)}
     >
diff --git a/apps/readest-app/src/app/library/components/ViewMenu.tsx b/apps/readest-app/src/app/library/components/ViewMenu.tsx
index 885d0a1b..ae3dbe22 100644
--- a/apps/readest-app/src/app/library/components/ViewMenu.tsx
+++ b/apps/readest-app/src/app/library/components/ViewMenu.tsx
@@ -1,4 +1,5 @@
 import React from 'react';
+import clsx from 'clsx';
 import { useRouter, useSearchParams } from 'next/navigation';
 import { useEnv } from '@/context/EnvContext';
 import { useSettingsStore } from '@/store/settingsStore';
@@ -15,17 +16,21 @@ import { navigateToLibrary } from '@/utils/nav';
 import NumberInput from '@/components/settings/NumberInput';
 import MenuItem from '@/components/MenuItem';
 import Menu from '@/components/Menu';
+import { useIsMobileViewport } from '@/hooks/useIsMobileViewport';
 
 interface ViewMenuProps {
   setIsDropdownOpen?: (isOpen: boolean) => void;
+  menuClassName?: string;
 }
 
-const ViewMenu: React.FC<ViewMenuProps> = ({ setIsDropdownOpen }) => {
+const ViewMenu: React.FC<ViewMenuProps> = ({ setIsDropdownOpen, menuClassName }) => {
   const _ = useTranslation();
   const router = useRouter();
   const searchParams = useSearchParams();
   const { envConfig } = useEnv();
   const { settings } = useSettingsStore();
+  const isPhoneViewport = useIsMobileViewport();
+  const isCompactViewport = useIsMobileViewport(1024);
 
   const viewMode = settings.libraryViewMode;
   const coverFit = settings.libraryCoverFit;
@@ -170,7 +175,7 @@ const ViewMenu: React.FC<ViewMenuProps> = ({ setIsDropdownOpen }) => {
 
   return (
     <Menu
-      className='view-menu dropdown-content no-triangle z-20 mt-2 shadow-2xl'
+      className={clsx('view-menu dropdown-content no-triangle z-20 mt-2 shadow-2xl', menuClassName)}
       onCancel={() => setIsDropdownOpen?.(false)}
     >
       {/* View Mode */}
@@ -201,11 +206,12 @@ const ViewMenu: React.FC<ViewMenuProps> = ({ setIsDropdownOpen }) => {
             value={columns}
             disabled={viewMode === 'list'}
             onChange={handleSetColumns}
-            min={window.innerWidth < 640 ? 1 : window.innerWidth < 1024 ? 2 : 3}
-            max={window.innerWidth < 640 ? 4 : window.innerWidth < 1024 ? 6 : 12}
+            min={isPhoneViewport ? 1 : isCompactViewport ? 2 : 3}
+            max={isPhoneViewport ? 4 : isCompactViewport ? 6 : 12}
           />
         }
         onClick={() => handleToggleAutoColumns()}
+        transient
       />
 
       {/* Book Covers */}
diff --git a/apps/readest-app/src/app/library/page.tsx b/apps/readest-app/src/app/library/page.tsx
index 6c9a0f89..c34aa2c8 100644
--- a/apps/readest-app/src/app/library/page.tsx
+++ b/apps/readest-app/src/app/library/page.tsx
@@ -122,6 +122,7 @@ import DropIndicator from '@/components/DropIndicator';
 import SettingsDialog from '@/components/settings/SettingsDialog';
 import ModalPortal from '@/components/ModalPortal';
 import TransferQueuePanel from './components/TransferQueuePanel';
+import { Overlay } from '@/components/Overlay';
 
 /** Skip tiny non-book artifacts during folder auto-scan (matches the manual import dialog default). */
 const AUTO_IMPORT_MIN_SIZE_BYTES = 20 * 1024;
@@ -158,6 +159,19 @@ const LAST_IMPORT_FOLDER_MIN_SIZE_KEY = 'readest:lastImportFolderMinSizeKB';
  * dialog forces the toggle ON regardless of this value.
  */
 const LAST_IMPORT_FOLDER_READ_IN_PLACE_KEY = 'readest:lastImportFolderReadInPlace';
+const LIBRARY_SIDEBAR_VISIBLE_KEY = 'readest:librarySidebarVisible';
+
+const readLibrarySidebarVisibility = (): boolean | null => {
+  if (typeof window === 'undefined') return null;
+  try {
+    const stored = window.localStorage.getItem(LIBRARY_SIDEBAR_VISIBLE_KEY);
+    if (stored === '1') return true;
+    if (stored === '0') return false;
+  } catch {
+    return null;
+  }
+  return null;
+};
 
 const LibraryPageWithSearchParams = () => {
   const searchParams = useSearchParams();
@@ -218,6 +232,10 @@ const LibraryPageContent = ({ searchParams }: { searchParams: ReadonlyURLSearchP
   const [isSelectNone, setIsSelectNone] = useState(false);
   const [showDetailsBook, setShowDetailsBook] = useState<Book | null>(null);
   const [failedImportsModal, setFailedImportsModal] = useState<FailedImport[] | null>(null);
+  const [isDesktopLibraryViewport, setDesktopLibraryViewport] = useState(true);
+  const [isLibrarySidebarDocked, setLibrarySidebarDockedState] = useState(true);
+  const [isLibrarySidebarDrawerOpen, setLibrarySidebarDrawerOpen] = useState(false);
+  const [isLibraryViewportResolved, setLibraryViewportResolved] = useState(false);
   // "Import from folder" dialog state. Held as a small object rather
   // than a boolean because we need a default starting directory to seed
   // the path field, and we want the dialog to remain mounted long
@@ -300,6 +318,51 @@ const LibraryPageContent = ({ searchParams }: { searchParams: ReadonlyURLSearchP
   useClipUrlIngress();
   useTransferQueue(libraryLoaded);
 
+  const setLibrarySidebarDocked = useCallback((visible: boolean) => {
+    setLibrarySidebarDockedState(visible);
+    if (typeof window === 'undefined') return;
+    try {
+      window.localStorage.setItem(LIBRARY_SIDEBAR_VISIBLE_KEY, visible ? '1' : '0');
+    } catch {
+      // localStorage can be unavailable in constrained webviews; the in-memory
+      // state still gives the user a working toggle for this session.
+    }
+  }, []);
+
+  useEffect(() => {
+    if (typeof window === 'undefined') return;
+    const mediaQuery = window.matchMedia('(min-width: 768px)');
+    const syncSidebarMode = () => {
+      const isDesktop = mediaQuery.matches;
+      setDesktopLibraryViewport(isDesktop);
+      setLibrarySidebarDrawerOpen(false);
+      if (isDesktop) {
+        setLibrarySidebarDockedState(readLibrarySidebarVisibility() ?? true);
+      }
+      setLibraryViewportResolved(true);
+    };
+
+    syncSidebarMode();
+    mediaQuery.addEventListener('change', syncSidebarMode);
+    return () => mediaQuery.removeEventListener('change', syncSidebarMode);
+  }, []);
+
+  const openLibrarySidebar = useCallback(() => {
+    if (isDesktopLibraryViewport) {
+      setLibrarySidebarDocked(true);
+    } else {
+      setLibrarySidebarDrawerOpen(true);
+    }
+  }, [isDesktopLibraryViewport, setLibrarySidebarDocked]);
+
+  const closeLibrarySidebar = useCallback(() => {
+    if (isDesktopLibraryViewport) {
+      setLibrarySidebarDocked(false);
+    } else {
+      setLibrarySidebarDrawerOpen(false);
+    }
+  }, [isDesktopLibraryViewport, setLibrarySidebarDocked]);
+
   const { pullLibrary, pushLibrary } = useBooksSync();
   // Library-scoped auto-sync for the active third-party cloud provider (WebDAV /
   // Google Drive): keeps library.json current on import / delete / book-close,
@@ -1595,6 +1658,11 @@ const LibraryPageContent = ({ searchParams }: { searchParams: ReadonlyURLSearchP
 
   const showBookshelf = libraryLoaded || libraryBooks.length > 0;
   const categoryFilter = ensureLibraryCategoryFilter(searchParams?.get('category'));
+  const isLibrarySidebarVisible = isDesktopLibraryViewport
+    ? isLibrarySidebarDocked
+    : isLibrarySidebarDrawerOpen;
+  const isLibrarySidebarDockedVisible = isDesktopLibraryViewport && isLibrarySidebarDocked;
+  const showLibraryHeader = !isLibrarySidebarVisible;
 
   return (
     <div
@@ -1606,21 +1674,39 @@ const LibraryPageContent = ({ searchParams }: { searchParams: ReadonlyURLSearchP
         appService?.hasRoundedWindow && isRoundedWindow && 'window-border rounded-window',
       )}
     >
-      <LibrarySidebar
-        books={libraryBooks}
-        isSelectMode={isSelectMode}
-        onPullLibrary={pullLibrary}
-        onImportBooksFromFiles={handleImportBooksFromFiles}
-        onImportBooksFromDirectory={
-          appService?.canReadExternalDir ? handleImportBooksFromDirectory : undefined
-        }
-        onImportBookFromUrl={isTauriAppPlatform() ? () => setShowImportFromUrl(true) : undefined}
-        onOpenCatalogManager={handleShowOPDSDialog}
-        onToggleSelectMode={() => handleSetSelectMode(!isSelectMode)}
-      />
+      {isLibrarySidebarVisible && (
+        <>
+          {!isDesktopLibraryViewport && (
+            <Overlay className='z-40 bg-black/20' onDismiss={closeLibrarySidebar} />
+          )}
+          <LibrarySidebar
+            books={libraryBooks}
+            isSelectMode={isSelectMode}
+            onPullLibrary={pullLibrary}
+            onImportBooksFromFiles={handleImportBooksFromFiles}
+            onImportBooksFromDirectory={
+              appService?.canReadExternalDir ? handleImportBooksFromDirectory : undefined
+            }
+            onImportBookFromUrl={
+              isTauriAppPlatform() ? () => setShowImportFromUrl(true) : undefined
+            }
+            onOpenCatalogManager={handleShowOPDSDialog}
+            onToggleSelectMode={() => handleSetSelectMode(!isSelectMode)}
+            onToggleSidebar={closeLibrarySidebar}
+            isViewportResolved={isLibraryViewportResolved}
+          />
+        </>
+      )}
       <div className='flex min-w-0 flex-1 flex-col overflow-hidden'>
         <div
-          className='relative top-0 z-40 w-full md:hidden'
+          className={clsx(
+            'relative top-0 z-40 w-full',
+            isLibraryViewportResolved
+              ? showLibraryHeader
+                ? 'block'
+                : 'hidden'
+              : 'block md:hidden',
+          )}
           role='banner'
           tabIndex={-1}
           aria-label={_('Library Header')}
@@ -1640,6 +1726,7 @@ const LibraryPageContent = ({ searchParams }: { searchParams: ReadonlyURLSearchP
             onToggleSelectMode={() => handleSetSelectMode(!isSelectMode)}
             onSelectAll={handleSelectAll}
             onDeselectAll={handleDeselectAll}
+            onToggleSidebar={openLibrarySidebar}
           />
           <progress
             aria-label={_('Library Sync Progress')}
@@ -1652,16 +1739,18 @@ const LibraryPageContent = ({ searchParams }: { searchParams: ReadonlyURLSearchP
             max='100'
           />
         </div>
-        <progress
-          aria-label={_('Library Sync Progress')}
-          aria-hidden={isSyncing ? 'false' : 'true'}
-          className={clsx(
-            'progress progress-success hidden h-1 rounded-none transition-opacity duration-200 md:block',
-            isSyncing ? 'opacity-100' : 'opacity-0',
-          )}
-          value={syncProgress * 100}
-          max='100'
-        />
+        {!showLibraryHeader && (
+          <progress
+            aria-label={_('Library Sync Progress')}
+            aria-hidden={isSyncing ? 'false' : 'true'}
+            className={clsx(
+              'progress progress-success hidden h-1 rounded-none transition-opacity duration-200 md:block',
+              isSyncing ? 'opacity-100' : 'opacity-0',
+            )}
+            value={syncProgress * 100}
+            max='100'
+          />
+        )}
         {(loading || isSyncing) && (
           <div className='fixed inset-0 z-50 flex items-center justify-center'>
             <Spinner loading />
@@ -1739,6 +1828,7 @@ const LibraryPageContent = ({ searchParams }: { searchParams: ReadonlyURLSearchP
                   handleLibraryNavigation={handleLibraryNavigation}
                   booksTransferProgress={booksTransferProgress}
                   handlePushLibrary={pushLibrary}
+                  sidebarVisible={isLibrarySidebarDockedVisible}
                 />
               </div>
             </div>
diff --git a/apps/readest-app/src/components/Dropdown.tsx b/apps/readest-app/src/components/Dropdown.tsx
index e397f5fc..080481b0 100644
--- a/apps/readest-app/src/components/Dropdown.tsx
+++ b/apps/readest-app/src/components/Dropdown.tsx
@@ -1,7 +1,14 @@
 import clsx from 'clsx';
-import React, { useState, isValidElement, ReactElement, ReactNode, useRef, useId } from 'react';
+import React, {
+  useState,
+  isValidElement,
+  ReactElement,
+  ReactNode,
+  useRef,
+  useId,
+  useEffect,
+} from 'react';
 import { useDropdownContext } from '@/context/DropdownContext';
-import { Overlay } from './Overlay';
 import MenuItem from './MenuItem';
 
 interface DropdownProps {
@@ -74,6 +81,7 @@ const Dropdown: React.FC<DropdownProps> = ({
   const dropdownId = useId();
   const context = useDropdownContext();
   const isOpen = context ? context.openDropdownId === dropdownId : false;
+  const hasOpenDropdown = context ? context.openDropdownId !== null : isOpen;
   const containerRef = useRef<HTMLDivElement>(null);
   const [isFocused, setIsFocused] = useState(false);
 
@@ -108,6 +116,21 @@ const Dropdown: React.FC<DropdownProps> = ({
     }
   };
 
+  useEffect(() => {
+    if (!isOpen) return;
+    const handlePointerDown = (event: PointerEvent) => {
+      if (containerRef.current?.contains(event.target as Node)) return;
+      if (event.target instanceof Element && event.target.closest('.dropdown-container') !== null) {
+        return;
+      }
+      setIsDropdownOpen(false);
+    };
+
+    document.addEventListener('pointerdown', handlePointerDown, true);
+    return () => document.removeEventListener('pointerdown', handlePointerDown, true);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [isOpen]);
+
   const childrenWithToggle = isValidElement(children)
     ? React.cloneElement(children, {
         ...(typeof children.type !== 'string' && {
@@ -120,8 +143,7 @@ const Dropdown: React.FC<DropdownProps> = ({
 
   return (
     <div ref={containerRef} className={clsx('dropdown-container flex', containerClassName)}>
-      {isOpen && <Overlay onDismiss={() => setIsDropdownOpen(false)} />}
-      <div className={clsx('relative', isOpen && 'z-50')}>
+      <div className={clsx('relative', isOpen ? 'z-[60]' : hasOpenDropdown && 'z-[70]')}>
         <button
           tabIndex={0}
           aria-haspopup='menu'
diff --git a/apps/readest-app/src/hooks/useIsMobileViewport.ts b/apps/readest-app/src/hooks/useIsMobileViewport.ts
index 020003f0..eced192d 100644
--- a/apps/readest-app/src/hooks/useIsMobileViewport.ts
+++ b/apps/readest-app/src/hooks/useIsMobileViewport.ts
@@ -1,9 +1,7 @@
 import { useEffect, useState } from 'react';
 
 export const useIsMobileViewport = (breakpoint = 640) => {
-  const readViewport = () =>
-    typeof window === 'undefined' ? false : window.innerWidth < breakpoint;
-  const [isMobileViewport, setIsMobileViewport] = useState(readViewport);
+  const [isMobileViewport, setIsMobileViewport] = useState(false);
 
   useEffect(() => {
     if (typeof window === 'undefined') return;