fix(D5): add responsive dashboard breakpoints

Move fixed shell dimensions into responsive classes so sub-1024px layouts hide the right panel, turn the sidebar into a bottom nav, and keep dashboard content usable with adaptive grids and horizontal screener scrolling.

Refs: docs/AUDIT_REDESIGN.md item D5.

Co-Authored-By: GPT-5 Codex <noreply@openai.com>

web/src/components/layout/AppShell.tsx

@@ -13,41 +13,19 @@ import { SettingsView }  from '../../views/SettingsView';
 
 export function AppShell() {
   return (
-    <div style={{
-      display: 'flex',
-      minHeight: '100vh',
-      background: '#F3F4F6',
-      fontFamily: "'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif",
-    }}>
+    <div className="dashboard-shell">
       {/* Fixed left sidebar */}
       <Sidebar />
 
       {/* Main area (right of sidebar) */}
-      <div style={{
-        marginLeft: 72,
-        flex: 1,
-        display: 'flex',
-        flexDirection: 'column',
-        minHeight: '100vh',
-        overflow: 'hidden',
-      }}>
+      <div className="dashboard-main">
         {/* Sticky header */}
         <Header />
 
         {/* Content row: main + right panel */}
-        <div style={{
-          flex: 1,
-          display: 'flex',
-          overflow: 'hidden',
-          minHeight: 0,
-        }}>
+        <div className="dashboard-content-row">
           {/* Scrollable main content */}
-          <main style={{
-            flex: 1,
-            overflowY: 'auto',
-            padding: '24px 24px 32px',
-            minWidth: 0,
-          }}>
+          <main className="dashboard-content">
             <Routes>
               <Route path="/"          element={<HomeView />} />
               <Route path="/portfolio" element={<PortfolioView />} />

web/src/components/layout/RightPanel.tsx

@@ -227,8 +227,7 @@ function NewsFeed() {
 
 export function RightPanel() {
   return (
-    <aside style={{
-      width: 308, minWidth: 308, maxWidth: 308,
+    <aside className="dashboard-right-panel" style={{
       background: '#ffffff',
       borderLeft: '1px solid #E5E7EB',
       display: 'flex',

web/src/components/layout/Sidebar.tsx

@@ -23,24 +23,9 @@ export function Sidebar() {
     : 'US';
 
   return (
-    <aside style={{
-      width: 72,
-      minHeight: '100vh',
-      background: '#ffffff',
-      borderRight: '1px solid #E5E7EB',
-      display: 'flex',
-      flexDirection: 'column',
-      alignItems: 'center',
-      paddingTop: 16,
-      paddingBottom: 20,
-      position: 'fixed',
-      left: 0,
-      top: 0,
-      bottom: 0,
-      zIndex: 50,
-    }}>
+    <aside className="trading-sidebar">
       {/* Logo */}
-      <div style={{
+      <div className="trading-sidebar-logo" style={{
         width: 40,
         height: 40,
         borderRadius: 10,
@@ -58,25 +43,18 @@ export function Sidebar() {
       </div>
 
       {/* Nav items */}
-      <nav style={{
-        flex: 1,
-        display: 'flex',
-        flexDirection: 'column',
-        width: '100%',
-        alignItems: 'center',
-        gap: 2,
-      }}>
+      <nav className="trading-sidebar-nav">
         {NAV.map(({ to, icon: Icon, label, end }) => (
           <NavLink
             key={to}
             to={to}
             end={end}
+            className="trading-sidebar-link"
             style={({ isActive }) => ({
               display: 'flex',
               flexDirection: 'column',
               alignItems: 'center',
               justifyContent: 'center',
-              width: '100%',
               padding: '10px 0 8px',
               gap: 3,
               borderLeft: isActive ? '3px solid #2563EB' : '3px solid transparent',
@@ -105,6 +83,7 @@ export function Sidebar() {
 
       {/* User avatar */}
       <div
+        className="trading-sidebar-avatar"
         title={`${user?.email ?? ''} — click to sign out`}
         onClick={handleSignOut}
         style={{

web/src/index.css

@@ -60,4 +60,128 @@ body {
 @keyframes spin {
   from { transform: rotate(0deg); }
   to   { transform: rotate(360deg); }
-}
+}
+
+.dashboard-shell {
+  display: flex;
+  min-height: 100vh;
+  background: #F3F4F6;
+  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
+}
+
+.dashboard-main {
+  margin-left: 72px;
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  min-height: 100vh;
+  overflow: hidden;
+}
+
+.dashboard-content-row {
+  flex: 1;
+  display: flex;
+  overflow: hidden;
+  min-height: 0;
+}
+
+.dashboard-content {
+  flex: 1;
+  overflow-y: auto;
+  padding: 24px 24px 32px;
+  min-width: 0;
+}
+
+.dashboard-right-panel {
+  width: 308px;
+  min-width: 308px;
+  max-width: 308px;
+}
+
+.trading-sidebar {
+  width: 72px;
+  min-height: 100vh;
+  background: #ffffff;
+  border-right: 1px solid #E5E7EB;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  padding-top: 16px;
+  padding-bottom: 20px;
+  position: fixed;
+  left: 0;
+  top: 0;
+  bottom: 0;
+  z-index: 50;
+}
+
+.trading-sidebar-nav {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  width: 100%;
+  align-items: center;
+  gap: 2px;
+}
+
+.trading-sidebar-link {
+  width: 100%;
+}
+
+@media (max-width: 1023px) {
+  .dashboard-shell {
+    padding-bottom: 68px;
+  }
+
+  .dashboard-main {
+    margin-left: 0;
+    min-width: 0;
+  }
+
+  .dashboard-content-row {
+    min-width: 0;
+  }
+
+  .dashboard-content {
+    padding: 16px 14px 24px;
+  }
+
+  .dashboard-right-panel {
+    display: none !important;
+  }
+
+  .trading-sidebar {
+    width: 100%;
+    min-height: 64px;
+    height: 64px;
+    top: auto;
+    right: 0;
+    bottom: 0;
+    flex-direction: row;
+    justify-content: center;
+    align-items: stretch;
+    padding: 0 8px;
+    border-right: 0;
+    border-top: 1px solid #E5E7EB;
+    overflow-x: auto;
+  }
+
+  .trading-sidebar-logo,
+  .trading-sidebar-avatar {
+    display: none !important;
+  }
+
+  .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;
+  }
+}

web/src/views/HomeView.tsx

@@ -534,7 +534,7 @@ function QuickStats({ symbol }: { symbol: string }) {
   ];
 
   return (
-    <div style={{ display: 'grid', gridTemplateColumns: 'repeat(4,1fr)', gap: 12, marginBottom: 20 }}>
+    <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fit, minmax(140px, 1fr))', gap: 12, marginBottom: 20 }}>
       {stats.map(s => (
         <div key={s.label} style={{
           background: '#fff',
@@ -605,7 +605,7 @@ function ResearchCards({
   ];
 
   return (
-    <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr 1fr', gap: 16 }}>
+    <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fit, minmax(220px, 1fr))', gap: 16 }}>
       {/* Company Profile */}
       <div style={{ background: '#fff', borderRadius: 12, border: '1px solid #E5E7EB', padding: 16 }}>
         <div style={{ fontSize: 13, fontWeight: 700, color: '#111827', marginBottom: 10 }}>

web/src/views/ScreenerView.tsx

@@ -265,7 +265,7 @@ export function ScreenerView() {
       )}
 
       {/* Results table */}
-      <div style={{ background: '#fff', borderRadius: 12, border: '1px solid #E5E7EB', overflow: 'hidden' }}>
+      <div style={{ background: '#fff', borderRadius: 12, border: '1px solid #E5E7EB', overflowX: 'auto', overflowY: 'hidden' }}>
         {/* Header */}
         <div style={{
           display: 'grid',