diff --git a/frontend/src/components/AppShell.vue b/frontend/src/components/AppShell.vue
index 2123194..24022f6 100644
--- a/frontend/src/components/AppShell.vue
+++ b/frontend/src/components/AppShell.vue
@@ -17,6 +17,22 @@ const route = useRoute()
 
 <style scoped>
 .fc-content {
+  /* The full brand mark as one large, faint backdrop behind every page,
+     pinned to the viewport so content scrolls over it. Opaque surfaces
+     (cards, the nav) cover it; it shows in the gutters and on bare page
+     ground. The series reader is immersive and skips the shell, so reading
+     is never drawn over it.
+
+     Faded by laying the page colour over it at 94%, NOT with `opacity` on an
+     overlay element: an overlay needs this element to be z-indexed above it,
+     which makes all page content one stacking context under the nav and can
+     trap an in-page overlay beneath it. A background changes no stacking.
+     The mark is gold and parchment, close to the text colours, so it has to
+     stay this faint to keep text over it readable. */
+  background:
+    linear-gradient(rgba(var(--v-theme-background), 0.94), rgba(var(--v-theme-background), 0.94)),
+    url('/logo.svg') center / min(88vmin, 1100px) no-repeat;
+  background-attachment: fixed;
   min-height: 100vh;
   /* NO padding-top: the TopNav is position:sticky, so it already reserves its
      own space in the v-app flex column — content flows directly below it. The