diff --git a/web/src/App.tsx b/web/src/App.tsx
index 0050f60..1195518 100644
--- a/web/src/App.tsx
+++ b/web/src/App.tsx
@@ -191,18 +191,16 @@ function App() {
         showMarketplaceTab,
         handleSignOut,
       }}>
-        {/* Critical system alert banner */}
-        {hasCriticalEvents && (
-          <div className="critical-alert-banner">
-            <span>⚠️</span>
-            <span>
-              SYSTEM ALERT: {recentCriticalEvents.length} CRITICAL ISSUES DETECTED — GO TO SETTINGS › ADMIN PANEL
-            </span>
-            <span>⚠️</span>
-          </div>
-        )}
-
-        <div>
+        <div className={`app-runtime${hasCriticalEvents ? ' has-critical-alert' : ''}`}>
+          {hasCriticalEvents && (
+            <a className="critical-alert-banner" href="/settings">
+              <span aria-hidden="true">⚠️</span>
+              <span>
+                System alert: {recentCriticalEvents.length} critical issues detected — go to Settings › Admin Panel
+              </span>
+              <span aria-hidden="true">⚠️</span>
+            </a>
+          )}
           <AppShell />
         </div>
 
diff --git a/web/src/components/ChatControl.tsx b/web/src/components/ChatControl.tsx
index 34ea06d..6aa42e3 100644
--- a/web/src/components/ChatControl.tsx
+++ b/web/src/components/ChatControl.tsx
@@ -546,8 +546,8 @@ export const ChatControl = ({ profiles, botState, onApplyProfile }: ChatControlP
                 variant="ghost"
                 style={{
                     position: 'fixed',
-                    bottom: '24px',
-                    right: '24px',
+                    bottom: 'var(--trading-assistant-bottom, 24px)',
+                    right: 'var(--trading-assistant-right, 24px)',
                     zIndex: 99999,
                     cursor: 'pointer',
                     background: 'none',
@@ -628,13 +628,13 @@ export const ChatControl = ({ profiles, botState, onApplyProfile }: ChatControlP
         />
         <div style={{
             position: 'fixed',
-            bottom: '24px',
-            right: '24px',
+            bottom: 'var(--trading-assistant-bottom, 24px)',
+            right: 'var(--trading-assistant-right, 24px)',
             zIndex: 999999,
             width: '460px',
-            maxWidth: 'calc(100vw - 48px)',
+            maxWidth: 'calc(100vw - 32px)',
             height: '640px',
-            maxHeight: 'calc(100vh - 48px)',
+            maxHeight: 'calc(100dvh - var(--trading-assistant-bottom, 24px) - 16px)',
             display: 'flex',
             flexDirection: 'column',
             borderRadius: '20px',
diff --git a/web/src/components/layout/AppShell.tsx b/web/src/components/layout/AppShell.tsx
index da1e934..bfdd1f4 100644
--- a/web/src/components/layout/AppShell.tsx
+++ b/web/src/components/layout/AppShell.tsx
@@ -3,7 +3,7 @@ import { Link, Routes, Route, Navigate, useLocation } from 'react-router-dom';
 import { Sidebar } from './Sidebar';
 import { Header } from './Header';
 import { RightPanel } from './RightPanel';
-import { Button } from '../ui/Primitives';
+import { Button, Skeleton } from '../ui/Primitives';
 import { getLegacySimpleRoute, getPlansRoute } from '../../views/tradePlansRoutes';
 
 const HomeView = lazy(() => import('../../views/HomeView').then((mod) => ({ default: mod.HomeView })));
@@ -22,8 +22,15 @@ function RouteFallback() {
       aria-live="polite"
       className="route-fallback route-fallback-inline"
     >
-      <div className="route-fallback-spinner" aria-hidden="true" />
-      <span>Loading workspace…</span>
+      <div className="route-fallback-status">
+        <div className="route-fallback-spinner" aria-hidden="true" />
+        <span>Loading workspace…</span>
+      </div>
+      <div className="route-fallback-preview" aria-hidden="true">
+        <Skeleton shape="text" className="route-fallback-title" />
+        <Skeleton className="route-fallback-card" />
+        <Skeleton className="route-fallback-card route-fallback-card-short" />
+      </div>
     </section>
   );
 }
diff --git a/web/src/index.css b/web/src/index.css
index 946fa41..b093a39 100644
--- a/web/src/index.css
+++ b/web/src/index.css
@@ -68,6 +68,12 @@
   --bl-radius-card: 0.875rem;
   --bl-input: var(--input);
   --bl-border-strong: var(--border-strong);
+  --trading-shell-sidebar-width: 76px;
+  --trading-shell-tablet-sidebar-width: 88px;
+  --trading-shell-right-panel-width: 308px;
+  --trading-shell-bottom-nav-height: 72px;
+  --trading-assistant-bottom: 24px;
+  --trading-assistant-right: 24px;
 
   font-synthesis: none;
   text-rendering: optimizeLegibility;
@@ -276,6 +282,11 @@ body {
   }
 }
 
+.app-runtime {
+  min-height: 100vh;
+  background: var(--background);
+}
+
 .dashboard-shell {
   display: flex;
   min-height: 100vh;
@@ -286,7 +297,7 @@ body {
 }
 
 .dashboard-main {
-  margin-left: 72px;
+  margin-left: var(--trading-shell-sidebar-width);
   flex: 1;
   display: flex;
   flex-direction: column;
@@ -299,6 +310,7 @@ body {
   display: flex;
   overflow: hidden;
   min-height: 0;
+  min-width: 0;
 }
 
 .dashboard-content {
@@ -307,16 +319,17 @@ body {
   overflow-x: hidden;
   padding: 32px 32px 40px;
   min-width: 0;
+  scrollbar-gutter: stable;
 }
 
 .dashboard-right-panel {
-  width: 308px;
-  min-width: 308px;
-  max-width: 308px;
+  width: var(--trading-shell-right-panel-width);
+  min-width: var(--trading-shell-right-panel-width);
+  max-width: var(--trading-shell-right-panel-width);
 }
 
 .trading-sidebar {
-  width: 76px;
+  width: var(--trading-shell-sidebar-width);
   min-height: 100vh;
   background: var(--sidebar);
   border-right: 1px solid var(--border);
@@ -407,12 +420,22 @@ body {
 }
 
 .route-fallback-inline {
+  flex-direction: column;
+  align-items: stretch;
   min-height: min(420px, calc(100vh - 180px));
-  gap: 12px;
+  gap: 18px;
+  padding: 24px;
   background: color-mix(in oklab, var(--card) 92%, var(--background));
   box-shadow: var(--card-shadow);
 }
 
+.route-fallback-status {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 12px;
+}
+
 .route-fallback-spinner {
   width: 18px;
   height: 18px;
@@ -422,6 +445,27 @@ body {
   animation: spin 0.8s linear infinite;
 }
 
+.route-fallback-preview {
+  display: grid;
+  gap: 12px;
+  width: min(560px, 100%);
+  margin-inline: auto;
+}
+
+.route-fallback-title {
+  width: 46%;
+  min-height: 0;
+}
+
+.route-fallback-card {
+  min-height: 92px;
+}
+
+.route-fallback-card-short {
+  min-height: 64px;
+  width: 78%;
+}
+
 .route-empty-state {
   min-height: 420px;
   flex-direction: column;
@@ -1414,27 +1458,33 @@ body {
 }
 
 .critical-alert-banner {
-  position: sticky;
-  top: 8px;
-  z-index: 9999;
+  position: relative;
+  z-index: 80;
   display: flex;
-  width: fit-content;
-  max-width: min(860px, calc(100vw - 32px));
-  margin: 10px auto 0;
+  width: 100%;
+  min-height: 44px;
+  max-width: none;
+  margin: 0;
   align-items: center;
   justify-content: center;
   gap: 10px;
-  border: 1px solid color-mix(in oklab, var(--destructive) 28%, var(--border));
-  border-radius: 18px;
-  background: color-mix(in oklab, var(--card) 92%, var(--destructive));
+  border: 0;
+  border-bottom: 1px solid color-mix(in oklab, var(--destructive) 26%, var(--border));
+  background: color-mix(in oklab, var(--card) 88%, var(--destructive));
   color: var(--destructive);
-  padding: 8px 18px;
+  padding: 9px 18px;
   text-align: center;
-  box-shadow: 0 14px 34px rgba(15, 23, 42, 0.10);
-  font-size: 10px;
+  text-decoration: none;
+  box-shadow: 0 10px 28px rgba(15, 23, 42, 0.08);
+  font-size: 12px;
   font-weight: 850;
-  letter-spacing: 0.08em;
-  text-transform: uppercase;
+  letter-spacing: 0.04em;
+  text-transform: none;
+}
+
+.critical-alert-banner:hover {
+  background: color-mix(in oklab, var(--card) 82%, var(--destructive));
+  color: var(--destructive);
 }
 
 .trade-plans-page > .grid {
@@ -1907,6 +1957,224 @@ body {
   }
 }
 
+/* Final chrome overrides: keep navigation, alerts, content, and assistant from colliding. */
+@media (max-width: 1279px) {
+  .dashboard-main {
+    margin-left: var(--trading-shell-tablet-sidebar-width);
+  }
+
+  .dashboard-right-panel {
+    --trading-shell-right-panel-width: 300px;
+  }
+}
+
+@media (min-width: 561px) and (max-width: 1023px) {
+  .dashboard-shell {
+    padding-bottom: 0;
+  }
+
+  .dashboard-main {
+    margin-left: var(--trading-shell-tablet-sidebar-width);
+  }
+
+  .dashboard-content {
+    padding: 24px 20px 36px;
+  }
+
+  .dashboard-right-panel {
+    display: none !important;
+  }
+
+  .trading-sidebar {
+    top: 0;
+    right: auto;
+    bottom: 0;
+    left: 0;
+    width: var(--trading-shell-tablet-sidebar-width);
+    height: auto;
+    min-height: 100vh;
+    flex-direction: column;
+    align-items: center;
+    justify-content: flex-start;
+    padding: 16px 8px;
+    border-top: 0;
+    border-right: 1px solid var(--border);
+    overflow-x: visible;
+  }
+}
+
+@media (max-width: 560px) {
+  :root {
+    --trading-assistant-bottom: calc(var(--trading-shell-bottom-nav-height) + 18px);
+    --trading-assistant-right: 16px;
+  }
+
+  .critical-alert-banner {
+    min-height: 52px;
+    padding: 8px 16px;
+    font-size: 11px;
+    line-height: 1.45;
+    letter-spacing: 0.03em;
+  }
+
+  .dashboard-shell {
+    padding-bottom: var(--trading-shell-bottom-nav-height);
+  }
+
+  .dashboard-main {
+    margin-left: 0;
+    min-width: 0;
+  }
+
+  .dashboard-content {
+    padding: 18px 16px calc(var(--trading-shell-bottom-nav-height) + 28px);
+  }
+
+  .dashboard-right-panel {
+    display: none !important;
+  }
+
+  .trading-sidebar {
+    width: 100%;
+    min-height: var(--trading-shell-bottom-nav-height);
+    height: var(--trading-shell-bottom-nav-height);
+    top: auto;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    flex-direction: row;
+    justify-content: center;
+    align-items: stretch;
+    padding: 0 max(8px, env(safe-area-inset-left)) env(safe-area-inset-bottom) max(8px, env(safe-area-inset-right));
+    border-right: 0;
+    border-top: 1px solid var(--border);
+    overflow-x: auto;
+  }
+
+  .trading-sidebar-nav {
+    flex: 0 1 auto;
+    flex-direction: row;
+    width: auto;
+    max-width: 100%;
+    align-items: stretch;
+    gap: 0;
+  }
+
+  .trading-sidebar-link {
+    width: 68px;
+    min-width: 68px;
+  }
+}
+
+/* Central shell sizing shared by the final breakpoint rules below. */
+@media (max-width: 1279px) {
+  .dashboard-main {
+    margin-left: var(--trading-shell-tablet-sidebar-width);
+  }
+
+  .dashboard-right-panel {
+    --trading-shell-right-panel-width: 300px;
+  }
+}
+
+@media (min-width: 561px) and (max-width: 1023px) {
+  .dashboard-shell {
+    padding-bottom: 0;
+  }
+
+  .dashboard-main {
+    margin-left: var(--trading-shell-tablet-sidebar-width);
+  }
+
+  .dashboard-content {
+    padding: 24px 20px 36px;
+  }
+
+  .dashboard-right-panel {
+    display: none !important;
+  }
+
+  .trading-sidebar {
+    top: 0;
+    right: auto;
+    bottom: 0;
+    left: 0;
+    width: var(--trading-shell-tablet-sidebar-width);
+    height: auto;
+    min-height: 100vh;
+    flex-direction: column;
+    align-items: center;
+    justify-content: flex-start;
+    padding: 16px 8px;
+    border-top: 0;
+    border-right: 1px solid var(--border);
+    overflow-x: visible;
+  }
+}
+
+@media (max-width: 560px) {
+  :root {
+    --trading-assistant-bottom: calc(var(--trading-shell-bottom-nav-height) + 18px);
+    --trading-assistant-right: 16px;
+  }
+
+  .critical-alert-banner {
+    min-height: 52px;
+    padding: 8px 16px;
+    font-size: 11px;
+    line-height: 1.45;
+    letter-spacing: 0.03em;
+  }
+
+  .dashboard-shell {
+    padding-bottom: var(--trading-shell-bottom-nav-height);
+  }
+
+  .dashboard-main {
+    margin-left: 0;
+    min-width: 0;
+  }
+
+  .dashboard-content {
+    padding: 18px 16px calc(var(--trading-shell-bottom-nav-height) + 28px);
+  }
+
+  .dashboard-right-panel {
+    display: none !important;
+  }
+
+  .trading-sidebar {
+    width: 100%;
+    min-height: var(--trading-shell-bottom-nav-height);
+    height: var(--trading-shell-bottom-nav-height);
+    top: auto;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    flex-direction: row;
+    justify-content: center;
+    align-items: stretch;
+    padding: 0 max(8px, env(safe-area-inset-left)) env(safe-area-inset-bottom) max(8px, env(safe-area-inset-right));
+    border-right: 0;
+    border-top: 1px solid var(--border);
+    overflow-x: auto;
+  }
+
+  .trading-sidebar-nav {
+    flex: 0 1 auto;
+    flex-direction: row;
+    width: auto;
+    max-width: 100%;
+    align-items: stretch;
+    gap: 0;
+  }
+
+  .trading-sidebar-link {
+    width: 68px;
+    min-width: 68px;
+  }
+}
+
 @media (max-width: 760px) {
   .markets-opportunity-grid,
   .screener-filter-row {