diff --git a/library/layouts/VerticalTabsLayout.vue b/library/layouts/VerticalTabsLayout.vue
index d6fbc02db..398a428ca 100644
--- a/library/layouts/VerticalTabsLayout.vue
+++ b/library/layouts/VerticalTabsLayout.vue
@@ -186,8 +186,9 @@
             <div class="vtl-rows" v-show="!grp.folder || !isFolderClosed(grp)">
               <button
                 v-for="row in grp.rows" :key="row.key" type="button" role="tab"
-                class="vtl-tab" :class="{ active: row.key === active }"
+                class="vtl-tab" :class="{ active: row.key === active, disabled: row.disabled }"
                 :aria-selected="String(row.key === active)"
+                :aria-disabled="row.disabled ? 'true' : null"
                 :tabindex="row.key === active ? 0 : -1"
                 :ref="el => registerTab(row.key, el)"
                 @click="pick(row.key)" @keydown="onKey($event)">
@@ -210,8 +211,9 @@
         <template v-else>
           <button
             v-for="row in items" :key="row.key" type="button" role="tab"
-            class="vtl-tab" :class="{ active: row.key === active }"
+            class="vtl-tab" :class="{ active: row.key === active, disabled: row.disabled }"
             :aria-selected="String(row.key === active)"
+            :aria-disabled="row.disabled ? 'true' : null"
             :tabindex="row.key === active ? 0 : -1"
             :ref="el => registerTab(row.key, el)"
             @click="pick(row.key)" @keydown="onKey($event)">
@@ -402,6 +404,10 @@ const VTL_SHADOW_CSS = `
 .vtl-tab:hover { background:var(--vtl-accented); color:#3b463d; }
 .vtl-tab:focus-visible { outline:2px solid var(--vtl-accent); outline-offset:-2px; }
 .vtl-tab.active { background:var(--vtl-accented); color:#3b463d; font-weight:500; }
+/* A DISABLED ROW (row.disabled, e.g. a desktop-only map on a phone) stays in the rail, greyed, with its badge
+   still readable. The click still reaches the consumer, so it can say WHY the row does not open. */
+.vtl-tab.disabled, .vtl-tab.disabled:hover { background:none; color:#a3a8a4; cursor:not-allowed; }
+.vtl-tab.disabled .vtl-tab-ic, .vtl-tab.disabled .vtl-tab-emoji, .vtl-tab.disabled .vtl-tab-fallback { opacity:.45; }
 .vtl-tab.active .vtl-tab-ic { color:var(--vtl-accent); }
 .vtl-tab-ic { flex:0 0 auto; display:inline-flex; color:var(--vtl-muted); }
 .vtl-tab-ic svg { width:20px; height:20px; }
@@ -505,13 +511,15 @@ const VTL_SHADOW_CSS = `
   /* MOBILE = the SAME composited-transform model, taken to its full-off-canvas extreme: a full-width
      drawer that slides in/out via transform (never a layout property), so opening/closing the drawer
      never reflows the content. Content is full-width (left:0) and stays put; the drawer floats over it. */
-  .vtl-nav { z-index:20; width:256px; box-shadow:0 0 28px rgba(0,0,0,.55); transform:translateX(-100%); }
+  /* NO SHADOW WHILE CLOSED: parked at translateX(-100%), a 28px blur still bleeds into the screen along the start
+     edge (measured at 390: the left 30px ~22 luminance levels darker). The shadow belongs to the OPEN drawer only. */
+  .vtl-nav { z-index:20; width:256px; box-shadow:none; transform:translateX(-100%); }
   /* OPEN DRAWER ABOVE THE PLUGIN'S OWN LAYERS. Mounted content shares this stacking context, and
      plugins raise their chrome (the research dashboard's filter bar is z-index:55), so at z-index 20
      the open drawer had a plugin's filter row painted across it — measured 2026-09-25 at 390px.
      Only while OPEN on a phone: that is when the drawer is the one thing you can use, and desktop
      and plugin modal scrims keep their existing order. */
-  .vtl.nav-open .vtl-nav { transform:translateX(0); z-index:1000; }
+  .vtl.nav-open .vtl-nav { transform:translateX(0); z-index:1000; box-shadow:0 0 28px rgba(0,0,0,.55); }
   .vtl-main { left:0; }
   /* The desktop slim-rail collapse has no meaning on a phone — reconcileForWidth() clears railCollapsed
      at this width, but neutralize its CSS too (belt-and-suspenders) so a full labelled drawer always
@@ -968,6 +976,10 @@ export default defineComponent({
 .vtl-tab:hover { background:var(--vtl-accented); color:#3b463d; }
 .vtl-tab:focus-visible { outline:2px solid var(--vtl-accent); outline-offset:-2px; }
 .vtl-tab.active { background:var(--vtl-accented); color:#3b463d; font-weight:500; }
+/* A DISABLED ROW (row.disabled, e.g. a desktop-only map on a phone) stays in the rail, greyed, with its badge
+   still readable. The click still reaches the consumer, so it can say WHY the row does not open. */
+.vtl-tab.disabled, .vtl-tab.disabled:hover { background:none; color:#a3a8a4; cursor:not-allowed; }
+.vtl-tab.disabled .vtl-tab-ic, .vtl-tab.disabled .vtl-tab-emoji, .vtl-tab.disabled .vtl-tab-fallback { opacity:.45; }
 .vtl-tab.active .vtl-tab-ic { color:var(--vtl-accent); }
 .vtl-tab-ic { flex:0 0 auto; display:inline-flex; color:var(--vtl-muted); }
 .vtl-tab-ic svg { width:20px; height:20px; }
@@ -1071,13 +1083,15 @@ export default defineComponent({
   /* MOBILE = the SAME composited-transform model, taken to its full-off-canvas extreme: a full-width
      drawer that slides in/out via transform (never a layout property), so opening/closing the drawer
      never reflows the content. Content is full-width (left:0) and stays put; the drawer floats over it. */
-  .vtl-nav { z-index:20; width:256px; box-shadow:0 0 28px rgba(0,0,0,.55); transform:translateX(-100%); }
+  /* NO SHADOW WHILE CLOSED: parked at translateX(-100%), a 28px blur still bleeds into the screen along the start
+     edge (measured at 390: the left 30px ~22 luminance levels darker). The shadow belongs to the OPEN drawer only. */
+  .vtl-nav { z-index:20; width:256px; box-shadow:none; transform:translateX(-100%); }
   /* OPEN DRAWER ABOVE THE PLUGIN'S OWN LAYERS. Mounted content shares this stacking context, and
      plugins raise their chrome (the research dashboard's filter bar is z-index:55), so at z-index 20
      the open drawer had a plugin's filter row painted across it — measured 2026-09-25 at 390px.
      Only while OPEN on a phone: that is when the drawer is the one thing you can use, and desktop
      and plugin modal scrims keep their existing order. */
-  .vtl.nav-open .vtl-nav { transform:translateX(0); z-index:1000; }
+  .vtl.nav-open .vtl-nav { transform:translateX(0); z-index:1000; box-shadow:0 0 28px rgba(0,0,0,.55); }
   .vtl-main { left:0; }
   /* The desktop slim-rail collapse has no meaning on a phone — reconcileForWidth() clears railCollapsed
      at this width, but neutralize its CSS too (belt-and-suspenders) so a full labelled drawer always