diff --git a/packages/ui/src/components/AppShell.tsx b/packages/ui/src/components/AppShell.tsx
index 8f4cea16..56f328a5 100644
--- a/packages/ui/src/components/AppShell.tsx
+++ b/packages/ui/src/components/AppShell.tsx
@@ -1,5 +1,3 @@
-'use client';
-
 import * as React from 'react';
 import { clsx } from 'clsx';
 import { Menu, X } from 'lucide-react';
@@ -8,42 +6,6 @@ type ShellStyle = React.CSSProperties & {
   '--bl-app-sidebar-width'?: string;
 };
 
-type ShellMediaQueryList = {
-  matches: boolean;
-  addEventListener?: (type: 'change', listener: () => void) => void;
-  removeEventListener?: (type: 'change', listener: () => void) => void;
-  addListener?: (listener: () => void) => void;
-  removeListener?: (listener: () => void) => void;
-};
-
-function useDesktopShell() {
-  const [isDesktop, setIsDesktop] = React.useState(false);
-
-  React.useEffect(() => {
-    const browser = globalThis as typeof globalThis & {
-      matchMedia?: (query: string) => ShellMediaQueryList;
-    };
-    const media = browser.matchMedia?.('(min-width: 1024px)');
-
-    if (!media) {
-      return undefined;
-    }
-
-    const sync = () => setIsDesktop(media.matches);
-
-    sync();
-    if (media.addEventListener && media.removeEventListener) {
-      media.addEventListener('change', sync);
-      return () => media.removeEventListener?.('change', sync);
-    }
-
-    media.addListener?.(sync);
-    return () => media.removeListener?.(sync);
-  }, []);
-
-  return isDesktop;
-}
-
 export interface AppShellProps extends React.HTMLAttributes<HTMLDivElement> {
   sidebarWidth?: number;
 }
@@ -63,12 +25,55 @@ export function AppShell({
   return (
     <div
       className={clsx(
-        'min-h-screen bg-[var(--bl-bg-canvas)] text-[var(--bl-text-primary)]',
+        'bl-app-shell min-h-screen bg-[var(--bl-bg-canvas)] text-[var(--bl-text-primary)]',
         className
       )}
       style={shellStyle}
       {...props}
     >
+      <style>
+        {`
+          .bl-app-shell-mobile-toggle {
+            display: inline-flex;
+          }
+
+          .bl-app-shell-overlay {
+            display: none;
+          }
+
+          .bl-app-shell-overlay[data-open="true"] {
+            display: block;
+          }
+
+          .bl-app-shell-sidebar {
+            transform: translateX(-100%);
+            transition: transform 200ms ease-out;
+          }
+
+          .bl-app-shell-sidebar[data-open="true"] {
+            transform: translateX(0);
+          }
+
+          .bl-app-shell-main {
+            padding: 4rem 1.25rem 1.25rem;
+          }
+
+          @media (min-width: 1024px) {
+            .bl-app-shell-mobile-toggle,
+            .bl-app-shell-overlay {
+              display: none !important;
+            }
+
+            .bl-app-shell-sidebar {
+              transform: translateX(0);
+            }
+
+            .bl-app-shell-main {
+              padding: 2rem 2rem 2rem calc(var(--bl-app-sidebar-width, 280px) + 2rem);
+            }
+          }
+        `}
+      </style>
       {children}
     </div>
   );
@@ -116,18 +121,12 @@ export function AppShellMobileToggle({
   children,
   ...props
 }: AppShellMobileToggleProps) {
-  const isDesktop = useDesktopShell();
-
-  if (isDesktop) {
-    return null;
-  }
-
   return (
     <button
       type="button"
       aria-label={open ? closeLabel : openLabel}
       className={clsx(
-        'fixed left-3 top-3 z-[38] inline-flex h-10 w-10 items-center justify-center',
+        'bl-app-shell-mobile-toggle fixed left-3 top-3 z-[38] h-10 w-10 items-center justify-center',
         'rounded-md border border-[var(--bl-border)] bg-[var(--bl-bg-elevated)]',
         'text-[var(--bl-text-primary)] shadow-sm transition-colors',
         'hover:bg-[var(--bl-surface-muted)] focus-visible:outline-none',
@@ -147,18 +146,12 @@ export interface AppShellOverlayProps extends React.HTMLAttributes<HTMLDivElemen
 }
 
 export function AppShellOverlay({ open, className, ...props }: AppShellOverlayProps) {
-  const isDesktop = useDesktopShell();
-
-  if (!open || isDesktop) {
-    return null;
-  }
-
   return (
     <div
       aria-hidden="true"
       data-open={open ? 'true' : 'false'}
       className={clsx(
-        'fixed inset-0 z-[39] bg-[var(--bl-overlay-scrim,rgba(0,0,0,0.5))]',
+        'bl-app-shell-overlay fixed inset-0 z-[39] bg-[var(--bl-overlay-scrim,rgba(0,0,0,0.5))]',
         className
       )}
       {...props}
@@ -181,15 +174,12 @@ export function AppShellSidebar({
   children,
   ...props
 }: AppShellSidebarProps) {
-  const isDesktop = useDesktopShell();
-  const isVisible = open || isDesktop;
-
   return (
     <aside
       aria-label={label}
       data-open={open ? 'true' : 'false'}
       className={clsx(
-        'fixed left-0 top-0 z-40 flex h-screen flex-col overflow-y-auto',
+        'bl-app-shell-sidebar fixed left-0 top-0 z-40 flex h-screen flex-col overflow-y-auto',
         'border-r border-[var(--bl-border)] bg-[var(--bl-surface-sidebar,var(--bl-bg-elevated))]',
         'transition-transform duration-200 ease-out lg:translate-x-0',
         className
@@ -197,8 +187,6 @@ export function AppShellSidebar({
       style={{
         width,
         minWidth: width,
-        transform: isVisible ? 'translateX(0)' : 'translateX(-100%)',
-        transition: 'transform 200ms ease-out',
         ...style,
       }}
       {...props}
@@ -220,19 +208,13 @@ export function AppShellMain({
   children,
   ...props
 }: AppShellMainProps) {
-  const isDesktop = useDesktopShell();
-
   return (
     <main
       id={id}
       tabIndex={-1}
       aria-labelledby={labelledBy}
-      className={clsx('min-h-screen min-w-0', className)}
-      style={{
-        padding: isDesktop ? '2rem' : '4rem 1.25rem 1.25rem',
-        paddingLeft: isDesktop ? 'calc(var(--bl-app-sidebar-width, 280px) + 2rem)' : '1.25rem',
-        ...style,
-      }}
+      className={clsx('bl-app-shell-main min-h-screen min-w-0', className)}
+      style={style}
       {...props}
     >
       <div className="grid gap-6">{children}</div>