Sidebar mobile improvement

The sidebar vanished on a too small display. Button to reopen and close
are rendered

frontend/src/lib.rs

@@ -84,9 +84,46 @@ pub struct SidebarShellProps {
 /// ```
 #[component(SidebarShell)]
 fn sidebar_shell(props: &SidebarShellProps) -> Html {
+    let route = use_route::<Route>();
+    let mobile_sidebar_open = use_state(|| false);
+
+    // Close mobile sidebar automatically on any route transition
+    {
+        let mobile_sidebar_open = mobile_sidebar_open.clone();
+        use_effect_with(route, move |_| {
+            mobile_sidebar_open.set(false);
+            || ()
+        });
+    }
+
+    let on_open = {
+        let mobile_sidebar_open = mobile_sidebar_open.clone();
+        Callback::from(move |_: MouseEvent| mobile_sidebar_open.set(true))
+    };
+
+    let on_close = {
+        let mobile_sidebar_open = mobile_sidebar_open.clone();
+        Callback::from(move |_: ()| mobile_sidebar_open.set(false))
+    };
+
+    let on_close_click = {
+        let on_close = on_close.clone();
+        Callback::from(move |_: MouseEvent| on_close.emit(()))
+    };
+
     html! {
         <div class="layout">
-            <sidebar::Sidebar/>
+            <button class="mobile-menu-toggle" onclick={on_open}>
+                <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                    <line x1="4" x2="20" y1="12" y2="12"/>
+                    <line x1="4" x2="20" y1="6" y2="6"/>
+                    <line x1="4" x2="20" y1="18" y2="18"/>
+                </svg>
+            </button>
+
+            <div class={if *mobile_sidebar_open { "sidebar-overlay open" } else { "sidebar-overlay" }} onclick={on_close_click}></div>
+
+            <sidebar::Sidebar is_open={*mobile_sidebar_open} on_close={on_close} />
             <main class="content">
                 { for props.children.iter() }
             </main>