diff --git a/.env b/.env
new file mode 100644
index 0000000..94a5fd7
--- /dev/null
+++ b/.env
@@ -0,0 +1,3 @@
+
+VITE_YAHOO_API_URL=https://query1.finance.yahoo.com
+VITE_YAHOO_ORIGIN=https://finance.yahoo.com
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index e721bab..1199dac 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -3,15 +3,14 @@ name: Deploy to GitHub Pages
 on:
   push:
     branches:
-      - main  # oder master, je nachdem welchen Branch-Namen Sie verwenden
-  workflow_dispatch: # Ermöglicht manuelles Triggern
+      - main
+  workflow_dispatch:
 
 permissions:
   contents: read
   pages: write
   id-token: write
 
-# Erlaubt nur einen gleichzeitigen Deploy
 concurrency:
   group: "pages"
   cancel-in-progress: true
@@ -39,6 +38,11 @@ jobs:
         run: npm run build
         env:
           VITE_BASE_URL: '/${{ github.event.repository.name }}'
+          VITE_YAHOO_API_URL: 'https://query1.finance.yahoo.com'
+          VITE_YAHOO_ORIGIN: 'https://finance.yahoo.com'
+
+      - name: Create 404.html
+        run: cp dist/index.html dist/404.html
 
       - name: Setup Pages
         uses: actions/configure-pages@v4
diff --git a/README.md b/README.md
index 669594a..7e2ecf0 100644
--- a/README.md
+++ b/README.md
@@ -12,8 +12,8 @@ Why this Project?
   - Portfolio Performance & Value
   - All assets (except the TTWOR and Portfolio-Value) are scaled by percentage of their price. Thus their referenced, scale is on the right. The referenced scale on the left is only for the portfolio-value
 
-![Dark Mode Preview](./preview-dark.png)
-![Light Mode Preview](./preview-light.png)
+![Dark Mode Preview](./docs/preview-dark.png)
+![Light Mode Preview](./docs/preview-light.png)
 
 ## Features
 
diff --git a/src/services/yahooFinanceService.ts b/src/services/yahooFinanceService.ts
index 4c51a0b..061a924 100644
--- a/src/services/yahooFinanceService.ts
+++ b/src/services/yahooFinanceService.ts
@@ -37,6 +37,8 @@ interface YahooChartResult {
   };
 }
 
+const API_BASE = import.meta.env.VITE_YAHOO_API_URL || '/yahoo';
+
 export const searchAssets = async (query: string): Promise<Asset[]> => {
   try {
     const params = new URLSearchParams({
@@ -45,7 +47,11 @@ export const searchAssets = async (query: string): Promise<Asset[]> => {
       type: 'equity,etf',
     });
 
-    const response = await fetch(`/yahoo/v1/finance/lookup?${params}`);
+    const response = await fetch(`${API_BASE}/v1/finance/lookup?${params}`, {
+      headers: {
+        'Origin': import.meta.env.VITE_YAHOO_ORIGIN || window.location.origin
+      }
+    });
     if (!response.ok) throw new Error('Network response was not ok');
 
     const data = await response.json() as YahooSearchResponse;
diff --git a/vite.config.ts b/vite.config.ts
index a396537..be1f3c8 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -1,24 +1,28 @@
-import { defineConfig } from "vite";
+import { defineConfig, loadEnv } from "vite";
 
 import react from "@vitejs/plugin-react";
 
 // https://vitejs.dev/config/
-export default defineConfig({
-  plugins: [react()],
-  optimizeDeps: {
-    exclude: ['lucide-react'],
-  },
-  server: {
-    proxy: {
-      '/yahoo': {
-        target: 'https://query1.finance.yahoo.com',
-        changeOrigin: true,
-        rewrite: (path) => path.replace(/^\/yahoo/, ''),
-        headers: {
-          'Origin': 'https://finance.yahoo.com'
+export default defineConfig(({ mode }) => {
+  const env = loadEnv(mode, process.cwd(), '');
+
+  return {
+    plugins: [react()],
+    optimizeDeps: {
+      exclude: ['lucide-react'],
+    },
+    server: {
+      proxy: {
+        '/yahoo': {
+          target: env.VITE_YAHOO_API_URL || 'https://query1.finance.yahoo.com',
+          changeOrigin: true,
+          rewrite: (path) => path.replace(/^\/yahoo/, ''),
+          headers: {
+            'Origin': env.VITE_YAHOO_ORIGIN || 'https://finance.yahoo.com'
+          }
         }
       }
-    }
-  },
-  base: process.env.VITE_BASE_URL || '/',
+    },
+    base: env.VITE_BASE_URL || '/',
+  };
 });