feat: flip card transition

frontend/src/app/recollections/FlippingCardView.tsx

@@ -0,0 +1,35 @@
+/**
+ * Flipping card container: Logos on the front, Flux on the back.
+ * Uses CSS 3D transform for a performant flip animation when switching via the menubar.
+ */
+
+import React from 'react'
+import { useLocation, useParams } from 'react-router-dom'
+import { LogosPage } from './logos/LogosPage'
+import { FluxRoute } from './flux/FluxRoute'
+
+export function FlippingCardView() {
+  const { pathname } = useLocation()
+  const { recollectionId } = useParams<{ recollectionId: string }>()
+  const isFlux = pathname.endsWith('/flux')
+
+  return (
+    <div
+      className="recollection-flip-container"
+      style={{ perspective: '1200px' }}
+    >
+      <div
+        className="recollection-flip-card"
+        data-flipped={isFlux}
+        aria-hidden={false}
+      >
+        <div className="recollection-flip-face recollection-flip-face-front">
+          <LogosPage />
+        </div>
+        <div className="recollection-flip-face recollection-flip-face-back">
+          {recollectionId && <FluxRoute />}
+        </div>
+      </div>
+    </div>
+  )
+}

frontend/src/app/recollections/RecollectionLayout.tsx

@@ -1,12 +1,13 @@
 /**
- * Layout for a single recollection: shared menubar (with optional custom content from active page) and outlet.
+ * Layout for a single recollection: shared menubar and flipping card (Logos front / Flux back).
  */
 
 import React, { useEffect } from 'react'
-import { Link, Outlet, useParams } from 'react-router-dom'
+import { Link, useParams } from 'react-router-dom'
 import { usePlatform } from '@/app/kosmos/KosmosContext'
 import { RecollectionMenubarProvider } from './RecollectionMenubarContext'
 import { RecollectionMenubar } from './RecollectionMenubar'
+import { FlippingCardView } from './FlippingCardView'
 
 export function RecollectionLayout() {
   const { recollectionId } = useParams<{ recollectionId: string }>()
@@ -35,7 +36,7 @@ export function RecollectionLayout() {
       <div className="flex min-h-0 flex-1 flex-col">
         <RecollectionMenubar />
         <div className="flex min-h-0 flex-1 flex-col overflow-hidden">
-          <Outlet />
+          <FlippingCardView />
         </div>
       </div>
     </RecollectionMenubarProvider>

frontend/src/app/recollections/RecollectionMenubar.tsx

@@ -3,7 +3,7 @@
  */
 
 import React from 'react'
-import { Link, NavLink, useParams } from 'react-router-dom'
+import { Link, NavLink, useParams, useLocation } from 'react-router-dom'
 import { usePlatform } from '@/app/kosmos/KosmosContext'
 import { ArrowLeft } from 'lucide-react'
 import { FluxIcon, LogosIcon } from '@/lib/icons'
@@ -11,14 +11,17 @@ import { useRecollectionMenubar } from './RecollectionMenubarContext'
 
 export function RecollectionMenubar() {
   const { recollectionId } = useParams<{ recollectionId: string }>()
+  const { pathname } = useLocation()
   const { recollections } = usePlatform()
   const { customContent } = useRecollectionMenubar()
 
+  const isFlux = pathname.endsWith('/flux')
   const recollection = recollectionId ? recollections.find((p) => p.id === recollectionId) : null
   const base = recollectionId ? `/recollections/${recollectionId}` : ''
   const defaultMiddle = recollection ? (
     <span className="truncate text-sm font-medium text-muted-foreground">{recollection.name}</span>
   ) : null
+  const middleContent = isFlux ? (customContent ?? defaultMiddle) : defaultMiddle
 
   return (
     <div className="flex h-9 w-full shrink-0 items-center gap-2 border-b border-border/40 bg-background px-2">
@@ -30,7 +33,7 @@ export function RecollectionMenubar() {
         <ArrowLeft className="size-4" />
       </Link>
       <div className="flex min-w-0 flex-1 items-center">
-        {customContent ?? defaultMiddle}
+        {middleContent}
       </div>
       {base && (
         <nav className="flex shrink-0 items-center gap-0.5" aria-label="Recollection pages">

frontend/src/main.tsx

@@ -8,8 +8,6 @@ import { registerBuiltinConfigTypes } from './lib/graph/configTypes'
 import { KosmosPage } from './app/kosmos/KosmosPage'
 import { RecollectionsPage } from './app/recollections/RecollectionsPage'
 import { RecollectionLayout } from './app/recollections/RecollectionLayout'
-import { LogosPage } from './app/recollections/logos/LogosPage'
-import { FluxRoute } from './app/recollections/flux/FluxRoute'
 import './lib/prismSetup'
 import 'prismjs/themes/prism.css'
 import './styles.css'
@@ -28,8 +26,8 @@ createRoot(document.getElementById('root')!).render(
             <Route path="recollections" element={<RecollectionsPage />} />
             <Route path="recollections/:recollectionId" element={<RecollectionLayout />}>
               <Route index element={<Navigate to="logos" replace />} />
-              <Route path="logos" element={<LogosPage />} />
+              <Route path="logos" element={<></>} />
-              <Route path="flux" element={<FluxRoute />} />
+              <Route path="flux" element={<></>} />
             </Route>
           </Route>
         </Routes>

frontend/src/styles.css

@@ -394,3 +394,40 @@ pre {
 .code-editor .token.url {
     background: none;
 }
+
+/* Recollection flipping card: Logos (front) / Flux (back). GPU-accelerated 3D flip. */
+.recollection-flip-container {
+    flex: 1;
+    min-height: 0;
+    overflow: hidden;
+}
+
+.recollection-flip-card {
+    width: 100%;
+    height: 100%;
+    position: relative;
+    transform-style: preserve-3d;
+    transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
+}
+
+.recollection-flip-card[data-flipped="true"] {
+    transform: rotateY(-180deg);
+}
+
+.recollection-flip-face {
+    position: absolute;
+    inset: 0;
+    width: 100%;
+    height: 100%;
+    backface-visibility: hidden;
+    -webkit-backface-visibility: hidden;
+    overflow: hidden;
+}
+
+.recollection-flip-face-front {
+    transform: rotateY(0deg);
+}
+
+.recollection-flip-face-back {
+    transform: rotateY(-180deg);
+}