Surface render crashes and make chat layout viewport-safe (#59)

The app had no error boundary, so any throw inside the dashboard unmounted the
whole tree and left a blank white page with no way to read the cause on a phone.
Add a route-scoped boundary that shows the failure details, and fix the chat
shell to fit small viewports: dynamic viewport height, shrinkable input row,
safe-area padding, and wrapping message bubbles.

Also pause the particle canvas while the tab is hidden and cap its particle
count so phones are not driving a needless animation loop.

llm-fe/src/App.tsx

@@ -23,6 +23,7 @@ import Tracker from './llm-fe/components/Tracker/Tracker';
 import { AnalyticsConsentProvider } from './llm-fe/contexts/AnalyticsConsentContext';
 import AnalyticsConsentBanner from './llm-fe/components/AnalyticsConsentBanner/AnalyticsConsentBanner';
 import AnalyticsSession from './llm-fe/components/AnalyticsSession/AnalyticsSession';
+import AppErrorBoundary from './llm-fe/components/AppErrorBoundary/AppErrorBoundary';
 
 const ProtectedRoutes = () => {
   const { authenticated, loading } = useContext(AuthContext);
@@ -53,6 +54,7 @@ class App extends Component {
             <div className="main-container">
 
 
+              <AppErrorBoundary>
               <Routes>
                 <Route path='*' element={<NotFound />} />
 
@@ -78,6 +80,7 @@ class App extends Component {
                 </Route>
 
               </Routes>
+              </AppErrorBoundary>
 
             </div>
 

llm-fe/src/llm-fe/components/AppErrorBoundary/AppErrorBoundary.test.tsx

@@ -0,0 +1,47 @@
+import React from 'react';
+import { render, screen } from '@testing-library/react';
+import { MemoryRouter } from 'react-router-dom';
+import AppErrorBoundary from './AppErrorBoundary';
+
+const Boom = (): JSX.Element => {
+  throw new Error('dashboard exploded');
+};
+
+describe('AppErrorBoundary', () => {
+  let consoleError: jest.SpyInstance;
+
+  beforeEach(() => {
+    consoleError = jest.spyOn(console, 'error').mockImplementation(() => undefined);
+  });
+
+  afterEach(() => {
+    consoleError.mockRestore();
+  });
+
+  it('renders children when nothing throws', () => {
+    render(
+      <MemoryRouter>
+        <AppErrorBoundary>
+          <div>chat loaded</div>
+        </AppErrorBoundary>
+      </MemoryRouter>,
+    );
+
+    expect(screen.getByText('chat loaded')).toBeInTheDocument();
+  });
+
+  it('shows the failure details instead of a blank screen', () => {
+    render(
+      <MemoryRouter>
+        <AppErrorBoundary>
+          <Boom />
+        </AppErrorBoundary>
+      </MemoryRouter>,
+    );
+
+    expect(screen.getByRole('alert')).toBeInTheDocument();
+    expect(screen.getByText(/Something broke on this screen/i)).toBeInTheDocument();
+    expect(screen.getByText(/dashboard exploded/)).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: /reload/i })).toBeInTheDocument();
+  });
+});

llm-fe/src/llm-fe/components/AppErrorBoundary/AppErrorBoundary.tsx

@@ -0,0 +1,133 @@
+import React, { Component, ErrorInfo, ReactNode } from 'react';
+import { useLocation } from 'react-router-dom';
+
+type BoundaryProps = {
+  children: ReactNode;
+};
+
+type BoundaryState = {
+  error: Error | null;
+  componentStack: string | null;
+};
+
+/**
+ * Without a boundary any render/effect throw unmounts the whole tree, which reads
+ * as a blank white page on mobile with no way to see the cause on the device.
+ */
+class ErrorBoundaryView extends Component<BoundaryProps, BoundaryState> {
+  constructor(props: BoundaryProps) {
+    super(props);
+    this.state = { error: null, componentStack: null };
+  }
+
+  static getDerivedStateFromError(error: Error): Partial<BoundaryState> {
+    return { error };
+  }
+
+  componentDidCatch(error: Error, errorInfo: ErrorInfo): void {
+    console.error('App crashed', error, errorInfo.componentStack);
+    this.setState({ componentStack: errorInfo.componentStack ?? null });
+  }
+
+  private details(): string {
+    const { error, componentStack } = this.state;
+    return [
+      `Page: ${window.location.href}`,
+      `Agent: ${navigator.userAgent}`,
+      `Error: ${error?.name ?? 'Error'}: ${error?.message ?? 'unknown'}`,
+      error?.stack ? `Stack:\n${error.stack}` : '',
+      componentStack ? `Components:${componentStack}` : '',
+    ]
+      .filter(Boolean)
+      .join('\n\n');
+  }
+
+  render(): ReactNode {
+    const { error } = this.state;
+    if (!error) {
+      return this.props.children;
+    }
+
+    return (
+      <div
+        role="alert"
+        style={{
+          minHeight: '100vh',
+          boxSizing: 'border-box',
+          padding: '1.5rem 1rem',
+          background: '#0f1220',
+          color: '#f5f6fa',
+          fontFamily: "'Inter', system-ui, sans-serif",
+          overflowWrap: 'anywhere',
+        }}
+      >
+        <div style={{ maxWidth: 640, margin: '0 auto' }}>
+          <h1 style={{ fontSize: '1.35rem', margin: '0 0 0.75rem' }}>Something broke on this screen</h1>
+          <p style={{ margin: '0 0 1rem', lineHeight: 1.5, color: 'rgba(245,246,250,0.75)' }}>
+            The rest of the app still works. Reload to try again, or copy the details below so the failure can be fixed.
+          </p>
+
+          <div style={{ display: 'flex', flexWrap: 'wrap', gap: '0.5rem', marginBottom: '1.25rem' }}>
+            <button
+              type="button"
+              onClick={() => window.location.reload()}
+              style={{
+                padding: '0.7rem 1.1rem',
+                borderRadius: '2rem',
+                border: 'none',
+                background: '#4c8dff',
+                color: '#fff',
+                fontWeight: 600,
+                cursor: 'pointer',
+              }}
+            >
+              Reload
+            </button>
+            <button
+              type="button"
+              onClick={() => {
+                void navigator.clipboard?.writeText(this.details());
+              }}
+              style={{
+                padding: '0.7rem 1.1rem',
+                borderRadius: '2rem',
+                border: '1px solid rgba(245,246,250,0.3)',
+                background: 'transparent',
+                color: '#f5f6fa',
+                fontWeight: 600,
+                cursor: 'pointer',
+              }}
+            >
+              Copy details
+            </button>
+          </div>
+
+          <pre
+            style={{
+              whiteSpace: 'pre-wrap',
+              fontSize: '0.8rem',
+              lineHeight: 1.5,
+              background: 'rgba(255,255,255,0.06)',
+              border: '1px solid rgba(255,255,255,0.12)',
+              borderRadius: '0.75rem',
+              padding: '1rem',
+              margin: 0,
+              maxHeight: '50vh',
+              overflow: 'auto',
+            }}
+          >
+            {this.details()}
+          </pre>
+        </div>
+      </div>
+    );
+  }
+}
+
+/** Route change clears a previous crash so navigation is never permanently stuck. */
+const AppErrorBoundary = ({ children }: BoundaryProps): JSX.Element => {
+  const location = useLocation();
+  return <ErrorBoundaryView key={location.pathname}>{children}</ErrorBoundaryView>;
+};
+
+export default AppErrorBoundary;

llm-fe/src/llm-fe/components/ConversationDetailCard/ConversationDetailCard.tsx

@@ -17,6 +17,8 @@ const MessageContainer = styled.div<{ $isUser: boolean }>`
 
 const Bubble = styled.div<{ $isUser: boolean }>`
   max-width: 80%;
+  min-width: 0;
+  overflow-wrap: anywhere;
   padding: 1rem 1.5rem;
   border-radius: 1.2rem;
   background: ${(props) =>
@@ -39,6 +41,7 @@ const Bubble = styled.div<{ $isUser: boolean }>`
     padding: 1rem;
     border-radius: 0.5rem;
     overflow-x: auto;
+    max-width: 100%;
   }
 
   & code {
@@ -50,6 +53,17 @@ const Bubble = styled.div<{ $isUser: boolean }>`
     color: #a0c4ff;
     text-decoration: underline;
   }
+
+  & img,
+  & table {
+    max-width: 100%;
+  }
+
+  @media (max-width: 768px) {
+    max-width: 92%;
+    padding: 0.75rem 1rem;
+    font-size: 0.95rem;
+  }
 `;
 
 const LoadingDot = styled.div`

llm-fe/src/llm-fe/components/Header2/Header2.tsx

@@ -12,26 +12,36 @@ const HeaderContainer = styled.header`
   top: 0;
   left: 0;
   width: 100%;
+  box-sizing: border-box;
   padding: 1rem 2rem;
+  padding-top: calc(1rem + env(safe-area-inset-top, 0px));
   display: flex;
   justify-content: space-between;
   align-items: center;
+  gap: 1rem;
   z-index: 100;
   background: ${({ theme }) => theme.darkMode ? 'rgba(0, 0, 0, 0.2)' : 'rgba(255, 255, 255, 0.2)'};
   backdrop-filter: blur(5px);
   border-bottom: 1px solid ${({ theme }) => theme.colors.cardBorder};
+
+  @media (max-width: 768px) {
+    padding: 0.75rem 1rem;
+    padding-top: calc(0.75rem + env(safe-area-inset-top, 0px));
+  }
 `;
 
 const Logo = styled.div`
   display: flex;
   align-items: center;
   gap: 0.65rem;
+  min-width: 0;
   cursor: pointer;
 `;
 
 const LogoMark = styled.img`
   width: 2rem;
   height: 2rem;
+  flex-shrink: 0;
   display: block;
   border-radius: 50%;
 `;
@@ -39,7 +49,12 @@ const LogoMark = styled.img`
 const LogoWordmark = styled.h4`
   margin: 0;
   font-size: 1.5rem;
+  white-space: nowrap;
   font-weight: 700;
+
+  @media (max-width: 768px) {
+    font-size: 1.25rem;
+  }
   color: ${({ theme }) => theme.colors.text};
   background: ${({ theme }) => `linear-gradient(135deg, ${theme.main} 0%, ${theme.focus} 100%)`};
   -webkit-background-clip: text;
@@ -100,7 +115,8 @@ const MobileMenuDropdown = styled.div<{ isOpen: boolean }>`
   top: 100%;
   left: 0;
   width: 100%;
-  background: ${({ theme }) => theme.colors.cardBackground};
+  box-sizing: border-box;
+  background: ${({ theme }) => theme.darkMode ? 'rgba(10, 12, 22, 0.97)' : 'rgba(255, 255, 255, 0.97)'};
   backdrop-filter: blur(10px);
   border-bottom: 1px solid ${({ theme }) => theme.colors.cardBorder};
   display: flex;

llm-fe/src/llm-fe/components/ParticleBackground/ParticleBackground.tsx

@@ -24,16 +24,20 @@ const ParticleBackground = () => {
         if (!ctx) return;
 
         let particles: Particle[] = [];
-        let animationFrameId: number;
+        let animationFrameId: number | null = null;
+        const prefersReducedMotion = window.matchMedia?.('(prefers-reduced-motion: reduce)').matches ?? false;
 
         const resizeCanvas = () => {
-            canvas.width = window.innerWidth;
+            const nextWidth = Math.max(1, window.innerWidth);
-            canvas.height = window.innerHeight;
+            const nextHeight = Math.max(1, window.innerHeight);
+            if (canvas.width === nextWidth && canvas.height === nextHeight) {
+                return;
+            }
+            canvas.width = nextWidth;
+            canvas.height = nextHeight;
+            init();
         };
 
-        window.addEventListener('resize', resizeCanvas);
-        resizeCanvas();
-
         class Particle {
             x: number;
             y: number;
@@ -73,18 +77,24 @@ const ParticleBackground = () => {
 
         const init = () => {
             particles = [];
-            const numberOfParticles = Math.floor((canvas.width * canvas.height) / 15000);
+            // Cap the count so the O(n^2) link pass stays cheap on phones.
+            const numberOfParticles = Math.min(
+                Math.floor((canvas.width * canvas.height) / 15000),
+                90,
+            );
             for (let i = 0; i < numberOfParticles; i++) {
                 particles.push(new Particle());
             }
         };
 
-        const animate = () => {
+        const render = (advance: boolean) => {
             if (!ctx) return;
             ctx.clearRect(0, 0, canvas.width, canvas.height);
 
             particles.forEach((particle) => {
-                particle.update();
+                if (advance) {
+                    particle.update();
+                }
                 particle.draw();
             });
 
@@ -111,16 +121,51 @@ const ParticleBackground = () => {
                     }
                 }
             }
+        };
 
+        const animate = () => {
+            render(true);
             animationFrameId = requestAnimationFrame(animate);
         };
 
+        const stop = () => {
+            if (animationFrameId !== null) {
+                cancelAnimationFrame(animationFrameId);
+                animationFrameId = null;
+            }
+        };
+
+        const start = () => {
+            if (animationFrameId !== null || prefersReducedMotion) {
+                return;
+            }
+            animate();
+        };
+
+        // A backgrounded tab keeps burning battery otherwise, which matters most on phones.
+        const handleVisibilityChange = () => {
+            if (document.hidden) {
+                stop();
+            } else {
+                start();
+            }
+        };
+
+        resizeCanvas();
         init();
-        animate();
+        if (prefersReducedMotion) {
+            render(false);
+        } else {
+            start();
+        }
+
+        window.addEventListener('resize', resizeCanvas);
+        document.addEventListener('visibilitychange', handleVisibilityChange);
 
         return () => {
             window.removeEventListener('resize', resizeCanvas);
-            cancelAnimationFrame(animationFrameId);
+            document.removeEventListener('visibilitychange', handleVisibilityChange);
+            stop();
         };
     }, [theme]); // Re-run when theme changes
 

llm-fe/src/llm-fe/pages/AsyncDashboard2/AsyncDashboard2.tsx

@@ -21,8 +21,11 @@ import { AnalyticsEvents, trackEvent } from "../../utils/analytics";
 // Styled Components
 const PageContainer = styled.div`
   position: relative;
-  width: 100vw;
+  width: 100%;
+  max-width: 100%;
   height: 100vh;
+  /* Mobile URL bars change the viewport height; dvh keeps the input row reachable. */
+  height: 100dvh;
   overflow: hidden;
   display: flex;
   color: ${({ theme }) => theme.colors.text};
@@ -32,6 +35,8 @@ const PageContainer = styled.div`
 
 const Sidebar = styled.div<{ $isOpen: boolean }>`
   width: 280px;
+  flex-shrink: 0;
+  box-sizing: border-box;
   height: 100%;
   background: ${({ theme }) => theme.darkMode ? 'rgba(0, 0, 0, 0.6)' : 'rgba(255, 255, 255, 0.6)'};
   backdrop-filter: blur(10px);
@@ -48,7 +53,9 @@ const Sidebar = styled.div<{ $isOpen: boolean }>`
     top: 0;
     left: 0;
     width: min(85vw, 320px);
-    height: 100vh;
+    height: 100dvh;
+    padding-top: calc(4.5rem + env(safe-area-inset-top, 0px));
+    padding-bottom: calc(1rem + env(safe-area-inset-bottom, 0px));
     transform: ${({ $isOpen }) => $isOpen ? 'translateX(0)' : 'translateX(-100%)'};
     background: ${({ theme }) => theme.darkMode ? 'rgba(0, 0, 0, 0.95)' : 'rgba(255, 255, 255, 0.95)'};
     box-shadow: ${({ $isOpen }) => $isOpen ? '0 0 20px rgba(0,0,0,0.5)' : 'none'};
@@ -59,7 +66,7 @@ const Sidebar = styled.div<{ $isOpen: boolean }>`
 const MobileSidebarToggle = styled.button`
   display: none;
   position: absolute;
-  top: 5.5rem; /* Below header */
+  top: calc(4.75rem + env(safe-area-inset-top, 0px)); /* Below header */
   left: 1rem;
   z-index: 15;
   padding: 0.5rem 1rem;
@@ -87,10 +94,7 @@ const MobileSidebarToggle = styled.button`
 const Overlay = styled.div<{ $isOpen: boolean }>`
   display: none;
   position: fixed;
-  top: 0;
+  inset: 0;
-  left: 0;
-  width: 100vw;
-  height: 100vh;
   background: rgba(0, 0, 0, 0.5);
   backdrop-filter: blur(2px);
   z-index: 110;
@@ -135,22 +139,35 @@ const MobileSidebarCloseButton = styled.button`
 
 const MainContent = styled.div`
   flex: 1;
+  min-width: 0;
   height: 100%;
   display: flex;
   flex-direction: column;
   position: relative;
   z-index: 5;
-  padding-top: 4rem; // Account for header
+  padding-top: calc(4rem + env(safe-area-inset-top, 0px)); // Account for header
+
+  @media (max-width: 768px) {
+    padding-top: calc(3.75rem + env(safe-area-inset-top, 0px));
+  }
 `;
 
 const ChatArea = styled.div`
   flex: 1;
+  min-height: 0;
   overflow-y: auto;
+  overflow-x: hidden;
+  overscroll-behavior: contain;
+  -webkit-overflow-scrolling: touch;
   padding: 2rem;
   display: flex;
   flex-direction: column;
   scroll-behavior: smooth;
 
+  @media (max-width: 768px) {
+    padding: 1rem 0.85rem;
+  }
+
   &::-webkit-scrollbar {
     width: 8px;
   }
@@ -164,14 +181,22 @@ const ChatArea = styled.div`
 `;
 
 const InputArea = styled.div`
+  flex-shrink: 0;
+  box-sizing: border-box;
   padding: 1.5rem 2rem;
   background: ${({ theme }) => theme.darkMode ? 'rgba(0, 0, 0, 0.4)' : 'rgba(255, 255, 255, 0.4)'};
   backdrop-filter: blur(5px);
   border-top: 1px solid ${({ theme }) => theme.colors.cardBorder};
+
+  @media (max-width: 768px) {
+    padding: 0.75rem 0.75rem calc(0.75rem + env(safe-area-inset-bottom, 0px));
+  }
 `;
 
 const StyledInputContainer = styled.div`
   position: relative;
+  box-sizing: border-box;
+  width: 100%;
   max-width: 900px;
   margin: 0 auto;
   background: ${({ theme }) => theme.darkMode ? 'rgba(255, 255, 255, 0.05)' : 'rgba(0, 0, 0, 0.05)'};
@@ -180,8 +205,14 @@ const StyledInputContainer = styled.div`
   padding: 0.5rem 1rem;
   display: flex;
   align-items: center;
+  gap: 0.25rem;
   transition: all 0.3s ease;
 
+  @media (max-width: 768px) {
+    padding: 0.35rem 0.5rem;
+    border-radius: 1.25rem;
+  }
+
   &:focus-within {
     background: ${({ theme }) => theme.darkMode ? 'rgba(255, 255, 255, 0.1)' : 'rgba(0, 0, 0, 0.1)'};
     border-color: ${({ theme }) => theme.main};
@@ -191,9 +222,11 @@ const StyledInputContainer = styled.div`
 
 const StyledInput = styled.textarea`
   flex: 1;
+  min-width: 0;
   background: transparent;
   border: none;
   color: ${({ theme }) => theme.colors.text};
+  /* Below 16px iOS/Android browsers zoom the page on focus. */
   font-size: 1rem;
   padding: 0.8rem;
   outline: none;
@@ -211,6 +244,7 @@ const StyledInput = styled.textarea`
 const IconButton = styled.button`
   background: transparent;
   border: none;
+  flex-shrink: 0;
   color: ${({ theme }) => theme.darkMode ? 'rgba(255, 255, 255, 0.6)' : 'rgba(0, 0, 0, 0.6)'};
   cursor: pointer;
   padding: 0.5rem;
@@ -234,6 +268,8 @@ const IconButton = styled.button`
 const StyledSelect = styled.select`
   background: transparent;
   border: none;
+  flex-shrink: 0;
+  max-width: 7rem;
   color: ${({ theme }) => theme.colors.text};
   font-size: 0.9rem;
   padding: 0.5rem;
@@ -241,6 +277,13 @@ const StyledSelect = styled.select`
   cursor: pointer;
   margin-right: 0.5rem;
   border-right: 1px solid ${({ theme }) => theme.colors.cardBorder};
+
+  @media (max-width: 768px) {
+    max-width: 5.5rem;
+    font-size: 0.8rem;
+    padding: 0.4rem 0.2rem;
+    margin-right: 0.25rem;
+  }
   
   option {
     background: ${({ theme }) => theme.colors.background || '#1a1a1a'};
@@ -320,9 +363,11 @@ type PromptValues = {
   modelName: string;
 };
 
-const AlwaysScrollToBottom = (): JSX.Element => {
+const AlwaysScrollToBottom = ({ trigger }: { trigger: string | number }): JSX.Element => {
-  const elementRef = useRef<any>();
+  const elementRef = useRef<HTMLDivElement>(null);
-  useEffect(() => elementRef.current?.scrollIntoView({ behavior: "smooth" }));
+  useEffect(() => {
+    elementRef.current?.scrollIntoView({ behavior: "smooth", block: "end" });
+  }, [trigger]);
   return <div ref={elementRef} />;
 };
 
@@ -500,7 +545,7 @@ const AsyncDashboardInner = (): JSX.Element => {
               <Markdown>Select a conversation or start a new one.</Markdown>
             </div>
           )}
-          <AlwaysScrollToBottom />
+          <AlwaysScrollToBottom trigger={`${conversationDetails.length}:${stateMessage.length}`} />
         </ChatArea>
 
         <InputArea>

llm-fe/src/llm-fe/platform/nativeSafeArea.css

@@ -7,8 +7,18 @@ html {
 body {
   /* Keyboard plugin resizes body; keep root scrollable within inset. */
   min-height: 100%;
+  /* Full-bleed page shells must never create a sideways scroll on phones. */
+  max-width: 100%;
+  overflow-x: hidden;
 }
 
 #root {
   min-height: 100%;
+  max-width: 100%;
+}
+
+*,
+*::before,
+*::after {
+  box-sizing: border-box;
 }