diff --git a/src/app/AppRouter.tsx b/src/app/AppRouter.tsx
index 8532425..712135d 100644
--- a/src/app/AppRouter.tsx
+++ b/src/app/AppRouter.tsx
@@ -20,14 +20,14 @@ function AppRouter() {
 
   useEffect(() => {
     // Apply theme to document and save preference
-    document.documentElement.setAttribute('data-theme', theme);
+    document.documentElement.dataset.theme = theme;
     localStorage.setItem('theme', theme);
   }, [theme]);
 
   useEffect(() => {
     // Handle hash-based navigation for sections
     const handleHashChange = () => {
-      const hash = window.location.hash.substring(1);
+      const hash = globalThis.location.hash.substring(1);
       if (hash) {
         setTimeout(() => {
           const element = document.getElementById(hash);
@@ -42,10 +42,10 @@ function AppRouter() {
     handleHashChange();
 
     // Listen for hash changes
-    window.addEventListener('hashchange', handleHashChange);
+    globalThis.addEventListener('hashchange', handleHashChange);
 
     return () => {
-      window.removeEventListener('hashchange', handleHashChange);
+      globalThis.removeEventListener('hashchange', handleHashChange);
     };
   }, []);
 
diff --git a/src/components/ThemeToggle.tsx b/src/components/ThemeToggle.tsx
index fd48ede..70d698d 100644
--- a/src/components/ThemeToggle.tsx
+++ b/src/components/ThemeToggle.tsx
@@ -1,10 +1,10 @@
 import React from 'react';
 import { getTexts } from '../config/texts';
 
-type Props = {
+type Props = Readonly<{
   theme: 'light' | 'dark';
   setTheme: React.Dispatch<React.SetStateAction<'light' | 'dark'>>;
-};
+}>;
 
 export default function ThemeToggle({
   theme,
diff --git a/src/components/layout/MobileMenu.tsx b/src/components/layout/MobileMenu.tsx
index addcf49..e1f798c 100644
--- a/src/components/layout/MobileMenu.tsx
+++ b/src/components/layout/MobileMenu.tsx
@@ -1,9 +1,9 @@
 import { useEffect, useRef } from 'react';
 
 type Props = {
-  menuItems: string[];
-  isOpen: boolean;
-  onItemClick: (section: string) => void;
+  readonly menuItems: string[];
+  readonly isOpen: boolean;
+  readonly onItemClick: (section: string) => void;
 };
 
 export default function MobileMenu({ menuItems, isOpen, onItemClick }: Props) {
diff --git a/src/pages/ImprintPage.tsx b/src/pages/ImprintPage.tsx
index f8adc79..cf21317 100644
--- a/src/pages/ImprintPage.tsx
+++ b/src/pages/ImprintPage.tsx
@@ -16,7 +16,7 @@ export default function ImprintPage() {
     return () => {
       const existingMeta = document.querySelector('meta[name="robots"]');
       if (existingMeta) {
-        document.head.removeChild(existingMeta);
+        existingMeta.remove();
       }
     };
   }, []);
@@ -63,8 +63,8 @@ export default function ImprintPage() {
 
             <div className="imprint-page__subsection">
               <h3 className="imprint-page__subsection-title">{texts.contentLiabilityTitle}</h3>
-              {texts.contentLiabilityText.map((text, index) => (
-                <p key={index} className="imprint-page__text">
+              {texts.contentLiabilityText.map((text) => (
+                <p key={text.substring(0, 50)} className="imprint-page__text">
                   {text}
                 </p>
               ))}
@@ -72,8 +72,8 @@ export default function ImprintPage() {
 
             <div className="imprint-page__subsection">
               <h3 className="imprint-page__subsection-title">{texts.copyrightTitle}</h3>
-              {texts.copyrightText.map((text, index) => (
-                <p key={index} className="imprint-page__text">
+              {texts.copyrightText.map((text) => (
+                <p key={text.substring(0, 50)} className="imprint-page__text">
                   {text}
                 </p>
               ))}
@@ -101,8 +101,8 @@ export default function ImprintPage() {
                 <h3 className="imprint-page__privacy-subtitle">{texts.detailedPrivacyPolicy.responsibleTitle}</h3>
                 <p className="imprint-page__privacy-text">{texts.detailedPrivacyPolicy.responsibleText}</p>
                 <div className="imprint-page__contact-info">
-                  {texts.detailedPrivacyPolicy.responsibleContact.split('\n').map((line, index) => (
-                    <p key={index} className="imprint-page__contact-line">{line}</p>
+                  {texts.detailedPrivacyPolicy.responsibleContact.split('\n').map((line) => (
+                    <p key={line.trim() || 'empty-line'} className="imprint-page__contact-line">{line}</p>
                   ))}
                 </div>
               </div>
@@ -118,8 +118,8 @@ export default function ImprintPage() {
                 <h3 className="imprint-page__privacy-subtitle">{texts.detailedPrivacyPolicy.rightsTitle}</h3>
                 <p className="imprint-page__privacy-text">{texts.detailedPrivacyPolicy.rightsIntro}</p>
                 <ul className="imprint-page__rights-list">
-                  {texts.detailedPrivacyPolicy.rights.map((right, index) => (
-                    <li key={index} className="imprint-page__rights-item">
+                  {texts.detailedPrivacyPolicy.rights.map((right) => (
+                    <li key={right.title} className="imprint-page__rights-item">
                       <strong>{right.title}:</strong> {right.text}
                     </li>
                   ))}
@@ -139,8 +139,8 @@ export default function ImprintPage() {
                 <h3 className="imprint-page__privacy-subtitle">{texts.detailedPrivacyPolicy.dataDeletionTitle}</h3>
                 <p className="imprint-page__privacy-text">{texts.detailedPrivacyPolicy.dataDeletionIntro}</p>
                 <ul className="imprint-page__deletion-list">
-                  {texts.detailedPrivacyPolicy.dataDeletionReasons.map((reason, index) => (
-                    <li key={index} className="imprint-page__deletion-item">{reason}</li>
+                  {texts.detailedPrivacyPolicy.dataDeletionReasons.map((reason) => (
+                    <li key={reason.substring(0, 50)} className="imprint-page__deletion-item">{reason}</li>
                   ))}
                 </ul>
                 <p className="imprint-page__privacy-text">{texts.detailedPrivacyPolicy.retentionText}</p>
@@ -153,8 +153,8 @@ export default function ImprintPage() {
                   {texts.detailedPrivacyPolicy.webhostingText}
                 </p>
                 <ul className="imprint-page__webhosting-list">
-                  {texts.detailedPrivacyPolicy.webhostingDataTypes.map((dataType, index) => (
-                    <li key={index} className="imprint-page__webhosting-item">{dataType}</li>
+                  {texts.detailedPrivacyPolicy.webhostingDataTypes.map((dataType) => (
+                    <li key={dataType} className="imprint-page__webhosting-item">{dataType}</li>
                   ))}
                 </ul>
                 <p className="imprint-page__privacy-text">{texts.detailedPrivacyPolicy.webhostingPurpose}</p>
@@ -164,8 +164,8 @@ export default function ImprintPage() {
                     <strong>{texts.detailedPrivacyPolicy.webhostingDataCategories.affectedData}</strong>
                   </p>
                   <ul className="imprint-page__category-list">
-                    {texts.detailedPrivacyPolicy.webhostingDataCategories.affectedDataList.map((item, index) => (
-                      <li key={index}>{item}</li>
+                    {texts.detailedPrivacyPolicy.webhostingDataCategories.affectedDataList.map((item) => (
+                      <li key={item}>{item}</li>
                     ))}
                   </ul>
                   <p><strong>{texts.detailedPrivacyPolicy.webhostingDataCategories.affectedPersons}</strong></p>
@@ -199,8 +199,8 @@ export default function ImprintPage() {
                 <div className="imprint-page__data-categories">
                   <p className="imprint-page__category-title"><strong>Betroffene Daten:</strong></p>
                   <ul className="imprint-page__category-list">
-                    {texts.detailedPrivacyPolicy.contactDataCategories.affectedData.map((item, index) => (
-                      <li key={index}>{item}</li>
+                    {texts.detailedPrivacyPolicy.contactDataCategories.affectedData.map((item) => (
+                      <li key={item}>{item}</li>
                     ))}
                   </ul>
                   <p><strong>Betroffene Personen: </strong>{texts.detailedPrivacyPolicy.contactDataCategories.affectedPersons}</p>
diff --git a/src/pages/PrivacyPolicy.tsx b/src/pages/PrivacyPolicy.tsx
index 41d714f..3c6e6fc 100644
--- a/src/pages/PrivacyPolicy.tsx
+++ b/src/pages/PrivacyPolicy.tsx
@@ -15,7 +15,7 @@ export default function PrivacyPolicy() {
     return () => {
       const existingMeta = document.querySelector('meta[name="robots"]');
       if (existingMeta) {
-        document.head.removeChild(existingMeta);
+        existingMeta.remove();
       }
     };
   }, []);
@@ -28,8 +28,8 @@ export default function PrivacyPolicy() {
       <h2>{texts.dataCollectionTitle}</h2>
       <p>{texts.dataCollectionText}</p>
       <ul>
-        {texts.dataCollectionList.map((item, index) => (
-          <li key={index}>{item}</li>
+        {texts.dataCollectionList.map((item) => (
+          <li key={item}>{item}</li>
         ))}
       </ul>
 
@@ -45,8 +45,8 @@ export default function PrivacyPolicy() {
       <h2>{texts.rightsTitle}</h2>
       <p>{texts.rightsText}</p>
       <ul>
-        {texts.rightsList.map((right, index) => (
-          <li key={index}>{right}</li>
+        {texts.rightsList.map((right) => (
+          <li key={right}>{right}</li>
         ))}
       </ul>
 
diff --git a/src/utils/scrollUtils.ts b/src/utils/scrollUtils.ts
index d2873b8..dd8b26c 100644
--- a/src/utils/scrollUtils.ts
+++ b/src/utils/scrollUtils.ts
@@ -16,7 +16,7 @@ export function scrollToSection(
     navigate(`/#${sectionId}`);
   } else {
     // Fallback: direct navigation without router
-    window.location.href = `/#${sectionId}`;
+    globalThis.location.href = `/#${sectionId}`;
   }
 }