diff --git a/public/components/dross_bubble.js b/public/components/dross_bubble.js
index 152fe54..5f9767f 100644
--- a/public/components/dross_bubble.js
+++ b/public/components/dross_bubble.js
@@ -57,6 +57,8 @@ export async function renderDrossBubble() {
   fab.addEventListener('click', () => { if (fab._moved) { fab._moved = false; return; } openPanel(); });
   closeBtn.addEventListener('click', closePanel);
   collapse.addEventListener('click', closePanel);
+  // Topbar ◆ button (and any caller) can summon/dismiss Dross.
+  window.addEventListener('dross-toggle', () => panel.classList.contains('open') ? closePanel() : openPanel());
 
   drag(fab, fab, true); drag(header, panel, false);
 
diff --git a/public/components/topbar.js b/public/components/topbar.js
index 5281070..51cf743 100644
--- a/public/components/topbar.js
+++ b/public/components/topbar.js
@@ -4,7 +4,7 @@
 import { el, mount, clear } from '../dom.js';
 import { navigate } from '../router.js';
 import { on } from '../state.js';
-import { toggleSidebar, toggleRail } from './chrome.js';
+import { toggleSidebar } from './chrome.js';
 import { api } from '../api.js';
 
 // Cluster health → topbar pill. Returns [status, label, title].
@@ -72,7 +72,7 @@ export function renderTopbar(root) {
     el('div', { class: 'topbar-spacer' }),
     clusterPill,
     bell,
-    el('button', { class: 'chrome-toggle', title: 'Toggle companion chat', onclick: toggleRail }, '◆'),
+    el('button', { class: 'chrome-toggle', title: 'Summon Dross', onclick: () => window.dispatchEvent(new CustomEvent('dross-toggle')) }, '◆'),
     el('button', { class: 'icon-btn', onclick: () => alert('Agent-switching ships post-Plan-2.') }, 'Owner')
   );
 
diff --git a/public/style.css b/public/style.css
index 438d91d..1e69878 100644
--- a/public/style.css
+++ b/public/style.css
@@ -29,20 +29,18 @@ html, body { margin: 0; padding: 0; height: 100%; background: var(--bg); color:
 
 #shell {
   display: grid;
-  grid-template-columns: var(--sidebar-w) 1fr var(--rail-w);
+  grid-template-columns: var(--sidebar-w) 1fr;
   grid-template-rows: var(--topbar-h) 1fr;
   grid-template-areas:
-    "topbar topbar topbar"
-    "sidebar main rail";
+    "topbar topbar"
+    "sidebar main";
   height: 100vh;
   width: 100vw;
 }
-#shell.rail-collapsed { grid-template-columns: var(--sidebar-w) 1fr var(--rail-w-min); }
 
 #topbar   { grid-area: topbar;  border-bottom: 1px solid var(--border); background: var(--panel); display: flex; align-items: center; padding: 0 16px; gap: 12px; }
 #sidebar  { grid-area: sidebar; border-right:  1px solid var(--border); background: var(--panel); overflow-y: auto; padding: 12px 0; }
 #main     { grid-area: main;    overflow-y: auto; padding: 24px 32px; }
-#rightrail{ grid-area: rail;    border-left:   1px solid var(--border); background: var(--panel); overflow: hidden; display: flex; flex-direction: column; }
 
 /* topbar */
 .brand { font-family: var(--font-display); font-weight: 700; letter-spacing: 0.18em; font-size: 14px; color: var(--accent); text-transform: uppercase; padding: 0 6px; }
@@ -483,15 +481,11 @@ ul.plain li:last-child { border-bottom: none; }
 /* ===== Collapsible chrome + responsive layout (Plan 6 polish) ===== */
 :root { --sidebar-w-min: 0px; }
 #shell { transition: grid-template-columns .22s ease; }
-#sidebar, #rightrail { transition: transform .22s ease; }
+#sidebar { transition: transform .22s ease; }
 
-/* Desktop collapse — shrink the grid columns */
-#shell.sidebar-collapsed { grid-template-columns: var(--sidebar-w-min) 1fr var(--rail-w); }
-#shell.sidebar-collapsed.rail-collapsed { grid-template-columns: var(--sidebar-w-min) 1fr var(--rail-w-min); }
-#shell.rail-collapsed { grid-template-columns: var(--sidebar-w) 1fr var(--rail-w-min); }
+/* Desktop collapse — shrink the sidebar column */
+#shell.sidebar-collapsed { grid-template-columns: var(--sidebar-w-min) 1fr; }
 #shell.sidebar-collapsed #sidebar { overflow: hidden; border-right: none; }
-/* Hide chat body when the rail is collapsed so the thin strip stays clean */
-#shell.rail-collapsed .rail-chat { display: none; }
 
 /* Topbar toggle buttons */
 .chrome-toggle {
@@ -514,13 +508,11 @@ body.drawer-open #scrim { opacity: 1; pointer-events: auto; }
 /* ---- Narrow / mobile / vertical: off-canvas drawers, single-column main ---- */
 @media (max-width: 860px) {
   #shell,
-  #shell.sidebar-collapsed,
-  #shell.rail-collapsed,
-  #shell.sidebar-collapsed.rail-collapsed {
+  #shell.sidebar-collapsed {
     grid-template-columns: 1fr;
     grid-template-areas: "topbar" "main";
   }
-  #sidebar, #rightrail {
+  #sidebar {
     position: fixed; top: var(--topbar-h); bottom: 0; z-index: 50;
   }
   #sidebar  { left: 0;  width: min(82vw, 300px); transform: translateX(-100%); border-right: 1px solid var(--border); }