Extract responsive Sidebar component; fix mobile scroll bleed

The mobile filter drawer let touch scrolling chain through to the page.
New components/Sidebar.tsx owns the drawer/sticky-column shell: locks page
scroll while open, contains overscroll, closes on Escape/overlay/resize to
lg, manages focus, and hides the closed drawer from tab order.
RecipeLayout now composes Sidebar + RecipesSidebar; filtering is unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: multica-agent <github@multica.ai>

.claude/CLAUDE.md

@@ -31,7 +31,8 @@ app/                          # Next.js App Router pages
 components/
   Header.tsx / Footer.tsx     # Site chrome
   RecipesClient.tsx           # Recipe listing with filter state
-  RecipeLayout.tsx            # Sidebar layout (mobile drawer, desktop persistent)
+  RecipeLayout.tsx            # Recipe listing layout: filter button, Sidebar + results
+  Sidebar.tsx                 # Responsive sidebar shell (mobile drawer, desktop sticky column)
   RecipesSidebar.tsx          # Search + category/tag facet lists with result counts
   FacetGroup.tsx              # Collapsible sidebar facet section
   ActiveFilters.tsx           # Removable chips for active filters (above results)

.claude/rules/architecture.md

@@ -3,6 +3,7 @@
 ## State and Data Flow
 
 - **RecipeLayout** owns sidebar open/close state; passes `handleFilterChange` (memoised with `useCallback`) down to RecipesSidebar
+- **Sidebar** is the generic shell: a modal drawer below `lg`, a sticky column at `lg`+. While open it locks page scroll, closes on Escape/overlay/resize to `lg`, and moves focus in (restoring it on close). Its body has `overscroll-contain` so drawer scrolling never chains to the page. `onClose` must be stable (`useCallback`) since its effects depend on it
 - **RecipesSidebar** owns local UI state (debounced search input, tag filter text, show-more toggles) and reports filter changes via `onFilterChange`
 - **RecipesClient** owns filter state (synced to the URL), the filtered recipe list, and facet counts (all memoised with `useMemo`). Each facet's counts apply every filter except its own; options with zero results are hidden
 - **ActiveFilters** renders removable chips for the active filters above the results grid

components/RecipeLayout.tsx

@@ -1,6 +1,7 @@
 'use client';
 
-import { useState, useCallback, useEffect, ReactNode } from 'react';
+import { useState, useCallback, ReactNode } from 'react';
+import Sidebar from './Sidebar';
 import RecipesSidebar from './RecipesSidebar';
 import type { FacetCounts, FilterState } from '@/lib/types';
 
@@ -29,33 +30,17 @@ export default function RecipeLayout({
     onFilterChange(newFilters);
   }, [onFilterChange]);
 
-  // Close the mobile drawer on Escape
-  useEffect(() => {
-    if (!sidebarOpen) return;
-    const handleKeyDown = (e: KeyboardEvent) => {
-      if (e.key === 'Escape') setSidebarOpen(false);
-    };
-    document.addEventListener('keydown', handleKeyDown);
-    return () => document.removeEventListener('keydown', handleKeyDown);
-  }, [sidebarOpen]);
+  const closeSidebar = useCallback(() => setSidebarOpen(false), []);
 
   const activeFilterCount =
     (filters.search ? 1 : 0) + (filters.category ? 1 : 0) + filters.selectedTags.length;
 
   return (
     <div>
-      {/* Mobile Overlay */}
-      {sidebarOpen && (
-        <div
-          className="lg:hidden fixed inset-0 bg-black/50 z-40"
-          onClick={() => setSidebarOpen(false)}
-          aria-hidden="true"
-        />
-      )}
-
       {/* Mobile filter button */}
       <div className="lg:hidden mb-4">
         <button
+          type="button"
           onClick={() => setSidebarOpen(true)}
           className="inline-flex items-center gap-2 rounded-lg border border-gray-300 dark:border-gray-700 px-4 py-2 text-sm font-medium text-gray-800 dark:text-gray-200 hover:bg-gray-50 dark:hover:bg-gray-800 transition-colors"
           aria-expanded={sidebarOpen}
@@ -74,55 +59,29 @@ export default function RecipeLayout({
       </div>
 
       <div className="flex lg:gap-10">
-        {/* Sidebar - sticky column on desktop (lg+), slide-out drawer on mobile */}
-        <aside
+        <Sidebar
           id="recipes-sidebar"
-          className={`
-            fixed inset-y-0 left-0 z-50 w-80 max-w-[85vw]
-            bg-white dark:bg-gray-900
-            transition-transform duration-300 ease-in-out
-            lg:sticky lg:top-8 lg:z-0 lg:w-64 lg:max-w-none lg:shrink-0 lg:self-start
-            lg:max-h-[calc(100vh-4rem)] lg:bg-transparent lg:translate-x-0 lg:transition-none
-            ${sidebarOpen ? 'translate-x-0' : '-translate-x-full'}
-          `}
-          aria-label="Recipe filters"
+          title="Filters"
+          open={sidebarOpen}
+          onClose={closeSidebar}
+          footer={
+            <button
+              type="button"
+              onClick={closeSidebar}
+              className="w-full rounded-lg bg-blue-600 px-4 py-2.5 text-sm font-semibold text-white hover:bg-blue-700 transition-colors"
+            >
+              Show {resultCount} {resultCount === 1 ? 'recipe' : 'recipes'}
+            </button>
+          }
         >
-          <div className="flex h-full flex-col lg:max-h-[calc(100vh-4rem)]">
-            {/* Mobile drawer header */}
-            <div className="lg:hidden flex items-center justify-between px-4 py-3 border-b border-gray-200 dark:border-gray-800">
-              <span className="text-base font-semibold text-gray-900 dark:text-white">Filters</span>
-              <button
-                onClick={() => setSidebarOpen(false)}
-                className="p-1 text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-200 rounded-md hover:bg-gray-100 dark:hover:bg-gray-800 transition-colors"
-                aria-label="Close filters"
-              >
-                <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true">
-                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
-                </svg>
-              </button>
-            </div>
-
-            <div className="flex-1 overflow-y-auto p-4 lg:p-0 lg:pr-2">
-              <RecipesSidebar
-                categories={categories}
-                tags={tags}
-                facetCounts={facetCounts}
-                filters={filters}
-                onFilterChange={handleFilterChange}
-              />
-            </div>
-
-            {/* Mobile drawer footer */}
-            <div className="lg:hidden border-t border-gray-200 dark:border-gray-800 p-4">
-              <button
-                onClick={() => setSidebarOpen(false)}
-                className="w-full rounded-lg bg-blue-600 px-4 py-2.5 text-sm font-semibold text-white hover:bg-blue-700 transition-colors"
-              >
-                Show {resultCount} {resultCount === 1 ? 'recipe' : 'recipes'}
-              </button>
-            </div>
-          </div>
-        </aside>
+          <RecipesSidebar
+            categories={categories}
+            tags={tags}
+            facetCounts={facetCounts}
+            filters={filters}
+            onFilterChange={handleFilterChange}
+          />
+        </Sidebar>
 
         {/* Main content */}
         <div className="flex-1 min-w-0">

components/Sidebar.tsx

@@ -0,0 +1,114 @@
+'use client';
+
+import { useEffect, useRef, type ReactNode } from 'react';
+
+interface SidebarProps {
+  id: string;
+  title: string;
+  open: boolean;
+  onClose: () => void;
+  footer?: ReactNode;
+  children: ReactNode;
+}
+
+// Matches Tailwind's `lg` breakpoint, where the sidebar becomes a persistent column
+const DESKTOP_QUERY = '(min-width: 1024px)';
+
+// Responsive sidebar: a modal drawer below `lg`, a sticky column at `lg` and up.
+// While the drawer is open the page behind it can't scroll, and scrolling inside
+// it never chains through to the page.
+export default function Sidebar({ id, title, open, onClose, footer, children }: SidebarProps) {
+  const panelRef = useRef<HTMLDivElement>(null);
+
+  // Lock page scroll, close on Escape, and move focus into the drawer while open
+  useEffect(() => {
+    if (!open) return;
+
+    const root = document.documentElement;
+    const previousOverflow = root.style.overflow;
+    root.style.overflow = 'hidden';
+
+    const previousFocus = document.activeElement as HTMLElement | null;
+    panelRef.current?.focus({ preventScroll: true });
+
+    const handleKeyDown = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') onClose();
+    };
+    document.addEventListener('keydown', handleKeyDown);
+
+    return () => {
+      root.style.overflow = previousOverflow;
+      document.removeEventListener('keydown', handleKeyDown);
+      previousFocus?.focus({ preventScroll: true });
+    };
+  }, [open, onClose]);
+
+  // The drawer only exists below `lg`; close it if the viewport grows past that
+  useEffect(() => {
+    if (!open) return;
+    const query = window.matchMedia(DESKTOP_QUERY);
+    const handleChange = () => {
+      if (query.matches) onClose();
+    };
+    handleChange();
+    query.addEventListener('change', handleChange);
+    return () => query.removeEventListener('change', handleChange);
+  }, [open, onClose]);
+
+  return (
+    <>
+      {open && (
+        <div
+          className="lg:hidden fixed inset-0 z-40 bg-black/50 overscroll-none"
+          onClick={onClose}
+          aria-hidden="true"
+        />
+      )}
+
+      <aside
+        id={id}
+        aria-label={title}
+        className={`
+          fixed inset-y-0 left-0 z-50 h-dvh w-80 max-w-[85vw]
+          bg-white dark:bg-gray-900 shadow-xl
+          transition-[transform,visibility] duration-300 ease-in-out
+          ${open ? 'visible translate-x-0' : 'invisible -translate-x-full'}
+          lg:visible lg:sticky lg:top-8 lg:z-0 lg:h-auto lg:max-h-[calc(100vh-4rem)] lg:w-64 lg:max-w-none
+          lg:shrink-0 lg:self-start lg:translate-x-0 lg:bg-transparent lg:shadow-none lg:transition-none
+        `}
+      >
+        <div
+          ref={panelRef}
+          tabIndex={-1}
+          className="flex h-full flex-col focus:outline-none lg:max-h-[calc(100vh-4rem)]"
+        >
+          {/* Drawer header (mobile only) */}
+          <div className="lg:hidden flex items-center justify-between px-4 py-3 border-b border-gray-200 dark:border-gray-800">
+            <span className="text-base font-semibold text-gray-900 dark:text-white">{title}</span>
+            <button
+              type="button"
+              onClick={onClose}
+              className="p-1 text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-200 rounded-md hover:bg-gray-100 dark:hover:bg-gray-800 transition-colors"
+              aria-label={`Close ${title.toLowerCase()}`}
+            >
+              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
+              </svg>
+            </button>
+          </div>
+
+          {/* Scrolls on its own; overscroll-contain stops it chaining to the page */}
+          <div className="min-h-0 flex-1 overflow-y-auto overscroll-contain p-4 lg:p-0 lg:pr-2">
+            {children}
+          </div>
+
+          {footer && (
+            <div className="lg:hidden border-t border-gray-200 dark:border-gray-800 p-4">
+              {footer}
+            </div>
+          )}
+        </div>
+      </aside>
+    </>
+  );
+}