diff --git a/backend/routes/clickTtHttpPageRoutes.js b/backend/routes/clickTtHttpPageRoutes.js
index 45d18fdf..619a4842 100644
--- a/backend/routes/clickTtHttpPageRoutes.js
+++ b/backend/routes/clickTtHttpPageRoutes.js
@@ -162,75 +162,61 @@ function rewriteFormActionsInHtml(html, proxyBaseUrl, pageBaseUrl, sid) {
 function injectProxyNavigationScript(html, proxyBaseUrl, pageBaseUrl, sid) {
   if (!html || !proxyBaseUrl || !pageBaseUrl) return html;
 
-  const script = `
-<script>
-(function () {
-  const PROXY_BASE_URL = ${JSON.stringify(proxyBaseUrl)};
-  const PAGE_BASE_URL = ${JSON.stringify(pageBaseUrl)};
-  const SID = ${JSON.stringify(sid || '')};
-
-  function normalizeUrl(value, base) {
-    if (!value) return null;
-    const trimmed = String(value).trim();
-    if (!trimmed || trimmed.startsWith('#') || trimmed.startsWith('javascript:')) return null;
-    try {
-      return new URL(trimmed, base || PAGE_BASE_URL).href;
-    } catch {
-      return null;
-    }
-  }
-
-  function shouldProxyUrl(value) {
-    return /(^|\\.)click-tt\\.de$|(^|\\.)httv\\.de$/i.test(new URL(value).hostname);
-  }
-
-  function buildProxyUrl(targetUrl) {
-    const separator = PROXY_BASE_URL.includes('?') ? '&' : '?';
-    return PROXY_BASE_URL + separator + 'url=' + encodeURIComponent(targetUrl) + (SID ? '&sid=' + encodeURIComponent(SID) : '');
-  }
-
-  function navigateViaProxy(targetUrl) {
-    if (!targetUrl) return false;
-    if (!shouldProxyUrl(targetUrl)) return false;
-    window.location.assign(buildProxyUrl(targetUrl));
-    return true;
-  }
-
-  function getSubmitTarget(form, submitter) {
-    const action = submitter && submitter.getAttribute && submitter.getAttribute('formaction');
-    if (action) return normalizeUrl(action, PAGE_BASE_URL);
-    return normalizeUrl(form.getAttribute('action') || PAGE_BASE_URL, PAGE_BASE_URL);
-  }
-
-  document.addEventListener('click', function (event) {
-    const anchor = event.target && event.target.closest ? event.target.closest('a[href]') : null;
-    if (!anchor) return;
-    if (event.defaultPrevented) return;
-    const targetUrl = normalizeUrl(anchor.getAttribute('href'), PAGE_BASE_URL);
-    if (!targetUrl || !shouldProxyUrl(targetUrl)) return;
-    event.preventDefault();
-    navigateViaProxy(targetUrl);
-  }, false);
-
-  document.addEventListener('submit', function (event) {
-    const form = event.target;
-    if (!form || !form.tagName || form.tagName.toLowerCase() !== 'form') return;
-    const submitter = event.submitter || null;
-    const targetUrl = getSubmitTarget(form, submitter);
-    if (!targetUrl || !shouldProxyUrl(targetUrl)) return;
-    form.setAttribute('action', buildProxyUrl(targetUrl));
-  }, true);
-
-  const nativeSubmit = HTMLFormElement.prototype.submit;
-  HTMLFormElement.prototype.submit = function patchedSubmit() {
-    const targetUrl = getSubmitTarget(this, null);
-    if (targetUrl && shouldProxyUrl(targetUrl)) {
-      this.setAttribute('action', buildProxyUrl(targetUrl));
-    }
-    return nativeSubmit.apply(this, arguments);
-  };
-})();
-</script>`;
+  const scriptContent = [
+    '(function(){',
+    `var PROXY_BASE_URL=${JSON.stringify(proxyBaseUrl)};`,
+    `var PAGE_BASE_URL=${JSON.stringify(pageBaseUrl)};`,
+    `var SID=${JSON.stringify(sid || '')};`,
+    'function normalizeUrl(value, base){',
+    'if(!value)return null;',
+    "var trimmed=String(value).trim();",
+    "if(!trimmed||trimmed.indexOf('#')===0||trimmed.indexOf('javascript:')===0)return null;",
+    'try{return new URL(trimmed, base||PAGE_BASE_URL).href;}catch(e){return null;}',
+    '}',
+    'function shouldProxyUrl(value){',
+    'try{var hostname=new URL(value).hostname;return /(^|\\\\.)click-tt\\\\.de$|(^|\\\\.)httv\\\\.de$/i.test(hostname);}catch(e){return false;}',
+    '}',
+    'function buildProxyUrl(targetUrl){',
+    "var separator=PROXY_BASE_URL.indexOf('?')>=0?'&':'?';",
+    "return PROXY_BASE_URL+separator+'url='+encodeURIComponent(targetUrl)+(SID?'&sid='+encodeURIComponent(SID):'');",
+    '}',
+    'function navigateViaProxy(targetUrl){',
+    'if(!targetUrl||!shouldProxyUrl(targetUrl))return false;',
+    'window.location.assign(buildProxyUrl(targetUrl));',
+    'return true;',
+    '}',
+    'function getSubmitTarget(form, submitter){',
+    "var action=submitter&&submitter.getAttribute?submitter.getAttribute('formaction'):null;",
+    'if(action)return normalizeUrl(action,PAGE_BASE_URL);',
+    "return normalizeUrl((form&&form.getAttribute?form.getAttribute('action'):null)||PAGE_BASE_URL,PAGE_BASE_URL);",
+    '}',
+    "document.addEventListener('click',function(event){",
+    "var anchor=event.target&&event.target.closest?event.target.closest('a[href]'):null;",
+    'if(!anchor||event.defaultPrevented)return;',
+    "var targetUrl=normalizeUrl(anchor.getAttribute('href'),PAGE_BASE_URL);",
+    'if(!targetUrl||!shouldProxyUrl(targetUrl))return;',
+    'event.preventDefault();',
+    'navigateViaProxy(targetUrl);',
+    '},false);',
+    "document.addEventListener('submit',function(event){",
+    'var form=event.target;',
+    "if(!form||!form.tagName||form.tagName.toLowerCase()!=='form')return;",
+    'var submitter=event.submitter||null;',
+    'var targetUrl=getSubmitTarget(form,submitter);',
+    'if(!targetUrl||!shouldProxyUrl(targetUrl))return;',
+    "form.setAttribute('action',buildProxyUrl(targetUrl));",
+    '},true);',
+    'if(window.HTMLFormElement&&window.HTMLFormElement.prototype&&window.HTMLFormElement.prototype.submit){',
+    'var nativeSubmit=window.HTMLFormElement.prototype.submit;',
+    'window.HTMLFormElement.prototype.submit=function patchedSubmit(){',
+    'var targetUrl=getSubmitTarget(this,null);',
+    "if(targetUrl&&shouldProxyUrl(targetUrl)){this.setAttribute('action',buildProxyUrl(targetUrl));}",
+    'return nativeSubmit.apply(this,arguments);',
+    '};',
+    '}',
+    '})();',
+  ].join('');
+  const script = `<script>${scriptContent}<\/script>`;
 
   if (/<\/body>/i.test(html)) {
     return html.replace(/<\/body>/i, `${script}</body>`);