add dockerfile

Caddyfile

@@ -0,0 +1,7 @@
+:80
+
+root * /usr/share/caddy
+file_server
+
+# Redirect all not-found routes to index.html (SPA fallback)
+try_files {path} /index.html

Dockerfile

@@ -0,0 +1,25 @@
+# Stage 1: Build the Vite React app
+FROM node:22-alpine AS builder
+
+WORKDIR /app
+
+# Install dependencies
+COPY package.json /app
+COPY yarn.lock /app
+RUN yarn install
+
+COPY . .
+RUN yarn build
+
+# Stage 2: Serve with Caddy
+FROM caddy:alpine
+
+# Copy built app to the web root
+COPY --from=builder /app/dist /usr/share/caddy
+
+# Add Caddyfile (for routing support)
+COPY Caddyfile /etc/caddy/Caddyfile
+
+EXPOSE 80
+
+CMD ["caddy", "run", "--config", "/etc/caddy/Caddyfile", "--adapter", "caddyfile"]

src/hooks/useIntersectionLoad.ts

@@ -48,7 +48,7 @@ export function useIntersectionLoad(
     observerRef.current = new IntersectionObserver(
       (entries) => {
         const entry = entries[0]
-        if (entry.isIntersecting) {
+        if (entry?.isIntersecting) {
           debouncedCallback()
         }
       },