fix(client): self-host fonts and drop the Replit banner script

client/index.html

@@ -7,20 +7,9 @@
       content="width=device-width, initial-scale=1.0, maximum-scale=1"
     />
     <link rel="icon" href="/favicon.ico" />
-    <link rel="preconnect" href="https://fonts.googleapis.com" />
-    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
-    <link
-      href="https://fonts.googleapis.com/css2?family=Architects+Daughter&family=DM+Sans:ital,opsz,wght@0,9..40,100..1000;1,9..40,100..1000&family=Fira+Code:wght@300..700&family=Geist+Mono:wght@100..900&family=Geist:wght@100..900&family=IBM+Plex+Mono:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;1,100;1,200;1,300;1,400;1,500;1,600;1,700&family=IBM+Plex+Sans:ital,wght@0,100..700;1,100..700&family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&family=JetBrains+Mono:ital,wght@0,100..800;1,100..800&family=Libre+Baskerville:ital,wght@0,400;0,700;1,400&family=Lora:ital,wght@0,400..700;1,400..700&family=Merriweather:ital,opsz,wght@0,18..144,300..900;1,18..144,300..900&family=Montserrat:ital,wght@0,100..900;1,100..900&family=Open+Sans:ital,wght@0,300..800;1,300..800&family=Outfit:wght@100..900&family=Oxanium:wght@200..800&family=Playfair+Display:ital,wght@0,400..900;1,400..900&family=Plus+Jakarta+Sans:ital,wght@0,200..800;1,200..800&family=Poppins:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&family=Roboto+Mono:ital,wght@0,100..700;1,100..700&family=Roboto:ital,wght@0,100..900;1,100..900&family=Source+Code+Pro:ital,wght@0,200..900;1,200..900&family=Source+Serif+4:ital,opsz,wght@0,8..60,200..900;1,8..60,200..900&family=Space+Grotesk:wght@300..700&family=Space+Mono:ital,wght@0,400;0,700;1,400;1,700&display=swap"
-      rel="stylesheet"
-    />
   </head>
   <body style="overflow-y: hidden;">
     <div id="root"></div>
     <script type="module" src="/src/main.tsx"></script>
-    <!-- This is a replit script which adds a banner on the top of the page when opened in development mode outside the replit environment -->
-    <script
-      type="text/javascript"
-      src="https://replit.com/public/js/replit-dev-banner.js"
-    ></script>
   </body>
 </html>

client/src/components/features/code-editor.tsx

@@ -335,7 +335,7 @@ export function CodeEditor({
       },
       fontSize: Math.round(initial.fs),
       lineHeight: Math.round(initial.lh),
-      fontFamily: "JetBrains Mono, Consolas, Monaco, monospace",
+      fontFamily: '"JetBrains Mono Variable", "JetBrains Mono", Consolas, Monaco, monospace',
       wordWrap: "on",
       scrollBeyondLastLine: false,
       automaticLayout: true,

client/src/index.css

@@ -1,4 +1,3 @@
-@import url("https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=JetBrains+Mono:wght@400;500&display=swap");
 @import "./styles/theme-tokens.css";
 @import "tailwindcss" source(none);
 @source "../index.html";
@@ -214,9 +213,9 @@ html, body {
   --sidebar-accent-foreground: hsl(142 86% 28%);
   --sidebar-border: hsl(0 0% 15%);
   --sidebar-ring: hsl(142 86% 28%);
-  --font-sans: Inter, system-ui, sans-serif;
+  --font-sans: "Inter Variable", Inter, system-ui, sans-serif;
   --font-serif: Georgia, serif;
-  --font-mono: JetBrains Mono, Consolas, Monaco, monospace;
+  --font-mono: "JetBrains Mono Variable", "JetBrains Mono", Consolas, Monaco, monospace;
   --radius: 0.5rem;
   /* Unified font-size scale — all sizes now scale with --ui-font-scale */
   --fs-sm: calc(14px * var(--ui-font-scale));

client/src/main.tsx

@@ -3,6 +3,9 @@ import "./lib/monaco-error-suppressor"; // Geändert von @/lib/...
 import editorWorker from "monaco-editor/esm/vs/editor/editor.worker?worker";
 import { createRoot } from "react-dom/client";
 import App from "./App";
+// Self-hosted fonts: the page must not depend on third-party hosts to load.
+import "@fontsource-variable/inter";
+import "@fontsource-variable/jetbrains-mono";
 import "./index.css";
 import { getCurrentFontScale, increaseFontScale, decreaseFontScale } from "./lib/font-scale-utils";
 import { isMac } from "./lib/platform";

client/src/styles/theme-tokens.css

@@ -130,8 +130,8 @@
   /* ═══════════════════════════════════════════════════════════
      FONT FAMILIES (constant, no scaling)
      ═══════════════════════════════════════════════════════════ */
-  --font-code: "JetBrains Mono", Consolas, Monaco, monospace;
-  --font-sans: var(--font-sans, Inter, system-ui, sans-serif);
+  --font-code: "JetBrains Mono Variable", "JetBrains Mono", Consolas, Monaco, monospace;
+  --font-sans: var(--font-sans, "Inter Variable", Inter, system-ui, sans-serif);
 }
 
 /* ═══════════════════════════════════════════════════════════

e2e/self-contained-page-load.spec.ts

@@ -0,0 +1,24 @@
+import { test, expect } from '@playwright/test';
+
+// The page must load from the UnoSim origin alone. A blocking third-party
+// stylesheet or script (formerly Google Fonts and a Replit banner) left the page
+// blank until its host answered, which made E2E runs flaky and breaks filtered
+// school networks.
+
+test('the start page loads without any third-party request', async ({ page, baseURL }) => {
+  const ownHost = new URL(baseURL ?? 'http://localhost:3000').host;
+  const thirdParty: string[] = [];
+  page.on('request', (request) => {
+    const url = new URL(request.url());
+    // HTTP and WebSocket requests to the UnoSim host are first-party; blob:/data: never leave the page.
+    if (['http:', 'https:', 'ws:', 'wss:'].includes(url.protocol) && url.host !== ownHost) {
+      thirdParty.push(request.url());
+    }
+  });
+
+  await page.goto('/');
+  await expect(page.getByRole('button', { name: /start simulation/i })).toBeVisible({ timeout: 15000 });
+  await page.evaluate(() => document.fonts.ready);
+
+  expect(thirdParty).toEqual([]);
+});

package.json

@@ -66,6 +66,8 @@
     "prepare": "husky"
   },
   "dependencies": {
+    "@fontsource-variable/inter": "5.3.0",
+    "@fontsource-variable/jetbrains-mono": "5.3.0",
     "@radix-ui/react-alert-dialog": "^1.1.7",
     "@radix-ui/react-checkbox": "^1.1.5",
     "@radix-ui/react-dialog": "^1.1.7",