diff --git a/public/app.js b/public/app.js
index 02dcd1d..bb9aab3 100644
--- a/public/app.js
+++ b/public/app.js
@@ -76,6 +76,14 @@ function renderSidebar() {
 
     sidebar.style.display = 'block';
 
+    // Sidebar Header
+    const sidebarHeader = document.createElement('div');
+    sidebarHeader.className = 'sidebar-header';
+    const headerTitle = document.createElement('h2');
+    headerTitle.textContent = 'Aktenübersicht';
+    sidebarHeader.appendChild(headerTitle);
+    sidebar.appendChild(sidebarHeader);
+
     chapters.forEach(chapter => {
         const sidebarItem = document.createElement('div');
         sidebarItem.className = `sidebar-item ${activeChapter === chapter ? 'active' : ''}`;
@@ -136,8 +144,8 @@ function renderTasks() {
 
         taskCard.innerHTML = `
             <div class="task-header">
-                <div class="task-title">Aufgabe</div>
-                <div class="task-points">⭐ ${task.points} Punkte</div>
+                <div class="task-title">Ermittlungsaufgabe</div>
+                <div class="task-points">${task.points} EP</div>
             </div>
             <div class="task-question">${task.question}</div>
             <div class="task-input-group">
@@ -156,7 +164,7 @@ function renderTasks() {
                 </button>
             </div>
             <div class="task-status" id="status-${task.id}">
-                ${hasAnswer && !task.isCorrect ? '❌ Falsch - versuche es nochmal!' : ''}
+                ${hasAnswer && !task.isCorrect ? '✗ Berechnung fehlerhaft. Bitte erneut prüfen.' : ''}
             </div>
         `;
 
@@ -181,14 +189,14 @@ async function checkAnswer(taskId) {
     const userAnswer = parseInt(input.value);
 
     if (isNaN(userAnswer)) {
-        status.textContent = 'Bitte gib eine Zahl ein!';
+        status.textContent = 'Ungültige Eingabe. Bitte eine Zahl eingeben.';
         status.className = 'task-status error';
         return;
     }
 
     // Prüfe ob Aufgabe bereits korrekt beantwortet wurde
     if (task.isCorrect === true) {
-        status.textContent = '✅ Diese Aufgabe wurde bereits richtig beantwortet!';
+        status.textContent = '✓ Fall bereits abgeschlossen.';
         status.className = 'task-status completed';
         return;
     }
@@ -211,11 +219,11 @@ async function checkAnswer(taskId) {
         calculateTotalPoints();
 
         if (data.correct) {
-            status.textContent = '🎉 Richtig! Super gemacht!';
+            status.textContent = '✓ Berechnung korrekt. Fall weiter bearbeiten.';
             status.className = 'task-status success';
 
             // Zeige Erfolgsnachricht
-            showMessage(`🎉 ${data.points} Quest-Punkte verdient!`, 'success');
+            showMessage(`✓ ${data.points} Ermittlungspunkte erhalten`, 'success');
 
             // Konfetti-Animation und Aufgabe verschwinden lassen
             const taskCard = document.getElementById(`task-${taskId}`);
@@ -231,7 +239,7 @@ async function checkAnswer(taskId) {
                 }, 1500);
             }
         } else {
-            status.textContent = '❌ Nicht ganz richtig. Versuch es nochmal!';
+            status.textContent = '✗ Berechnung fehlerhaft. Bitte erneut prüfen.';
             status.className = 'task-status error';
             input.focus();
         }
@@ -244,7 +252,7 @@ async function checkAnswer(taskId) {
         }
     } catch (error) {
         console.error('Fehler beim Prüfen der Antwort:', error);
-        status.textContent = 'Fehler beim Prüfen. Bitte versuche es erneut.';
+        status.textContent = 'Systemfehler. Bitte erneut versuchen.';
         status.className = 'task-status error';
     }
 }
@@ -273,7 +281,7 @@ function updateProgress() {
 
 // Erstelle Konfetti-Animation
 function createConfetti(element) {
-    const colors = ['#ffd700', '#ff6b6b', '#4ecdc4', '#45b7d1', '#f9ca24', '#f0932b', '#eb4d4b', '#6c5ce7'];
+    const colors = ['#3498db', '#2980b9', '#34495e', '#2c3e50', '#1a252f', '#27ae60', '#16a085', '#7f8c8d'];
     const confettiCount = 50;
     
     // Hole Position des Elements
diff --git a/public/index.html b/public/index.html
index 41ea2aa..fa2b8a1 100644
--- a/public/index.html
+++ b/public/index.html
@@ -3,7 +3,7 @@
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>MathQuest - Mathe lernen mit Quest-Punkten!</title>
+    <title>Kriminalfälle - Mathematische Ermittlungen</title>
     <link rel="stylesheet" href="style.css">
 </head>
 <body>
@@ -14,19 +14,23 @@
         <div class="main-content">
             <div class="container">
                 <header>
-                    <h1>🌟 MathQuest 🌟</h1>
-                    <div class="points-display">
-                        <div class="points-label">Quest-Punkte</div>
-                        <div class="points-value" id="totalPoints">0</div>
+                    <div class="header-content">
+                        <h1>Kriminalfälle - Mathematische Ermittlungen</h1>
+                        <div class="points-display">
+                            <div class="points-label">Ermittlungspunkte</div>
+                            <div class="points-value" id="totalPoints">0</div>
+                        </div>
                     </div>
                 </header>
 
                 <div class="progress-section">
-                    <div class="progress-label">Fortschritt</div>
-                    <div class="progress-bar-container">
-                        <div class="progress-bar" id="progressBar"></div>
+                    <div class="progress-content">
+                        <div class="progress-label">Ermittlungsfortschritt</div>
+                        <div class="progress-bar-container">
+                            <div class="progress-bar" id="progressBar"></div>
+                        </div>
+                        <div class="progress-text" id="progressText">0 / 100</div>
                     </div>
-                    <div class="progress-text" id="progressText">0 / 100</div>
                 </div>
 
                 <div class="task-section">
diff --git a/public/style.css b/public/style.css
index a00dec5..ca76ef1 100644
--- a/public/style.css
+++ b/public/style.css
@@ -5,177 +5,212 @@
 }
 
 body {
-    font-family: 'Comic Sans MS', 'Chalkboard SE', 'Comic Neue', cursive, sans-serif;
-    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+    font-family: 'Arial', 'Helvetica', sans-serif;
+    background: #2c3e50;
     min-height: 100vh;
     padding: 0;
     margin: 0;
-    color: #333;
+    color: #1a1a1a;
 }
 
 .app-wrapper {
     display: flex;
     min-height: 100vh;
-    gap: 20px;
-    padding: 20px;
+    gap: 0;
+    padding: 0;
 }
 
 .sidebar {
     width: 280px;
-    background: white;
-    border-radius: 20px;
-    padding: 20px;
-    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
+    background: #34495e;
+    border-right: 3px solid #1a252f;
+    padding: 0;
     position: sticky;
-    top: 20px;
-    height: fit-content;
-    max-height: calc(100vh - 40px);
+    top: 0;
+    height: 100vh;
     overflow-y: auto;
+    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.3);
+}
+
+.sidebar-header {
+    background: #1a252f;
+    padding: 20px;
+    border-bottom: 2px solid #0f1419;
+}
+
+.sidebar-header h2 {
+    color: #ecf0f1;
+    font-size: 1.2em;
+    font-weight: bold;
+    text-transform: uppercase;
+    letter-spacing: 1px;
 }
 
 .sidebar-item {
-    padding: 15px;
-    margin-bottom: 10px;
-    border-radius: 10px;
+    padding: 15px 20px;
     cursor: pointer;
-    transition: all 0.3s ease;
-    background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
-    border: 2px solid transparent;
+    transition: background-color 0.2s;
+    border-bottom: 1px solid #2c3e50;
+    background: #34495e;
+    color: #ecf0f1;
 }
 
 .sidebar-item:hover {
-    transform: translateX(5px);
-    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
+    background: #3d566e;
 }
 
 .sidebar-item.active {
-    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
-    color: white;
-    border-color: rgba(255, 255, 255, 0.3);
-    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
+    background: #1a252f;
+    border-left: 4px solid #3498db;
+    color: #ecf0f1;
+    font-weight: bold;
 }
 
 .sidebar-item-title {
-    font-size: 1.1em;
-    font-weight: bold;
-    margin-bottom: 5px;
+    font-size: 0.95em;
+    line-height: 1.4;
 }
 
 .main-content {
     flex: 1;
     min-width: 0;
+    background: #ecf0f1;
 }
 
 .container {
     max-width: 100%;
-    background: white;
-    border-radius: 20px;
-    padding: 30px;
-    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
+    background: #ffffff;
+    padding: 0;
+    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
+    min-height: 100vh;
 }
 
 header {
-    text-align: center;
-    margin-bottom: 30px;
+    background: #1a252f;
+    padding: 25px 40px;
+    border-bottom: 4px solid #3498db;
+    color: #ecf0f1;
+}
+
+.header-content {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    max-width: 1200px;
+    margin: 0 auto;
 }
 
 h1 {
-    font-size: 2.5em;
-    color: #667eea;
-    margin-bottom: 20px;
-    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
+    font-size: 1.8em;
+    color: #ecf0f1;
+    margin: 0;
+    font-weight: bold;
+    text-transform: uppercase;
+    letter-spacing: 2px;
 }
 
 .points-display {
-    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
-    padding: 20px;
-    border-radius: 15px;
-    color: white;
-    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
-}
-
-.points-label {
-    font-size: 1.2em;
-    margin-bottom: 10px;
-}
-
-.points-value {
-    font-size: 3em;
-    font-weight: bold;
-    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
-}
-
-.progress-section {
-    margin-bottom: 30px;
+    background: #2c3e50;
+    padding: 15px 25px;
+    border: 2px solid #3498db;
+    border-radius: 4px;
     text-align: center;
 }
 
+.points-label {
+    font-size: 0.85em;
+    color: #bdc3c7;
+    text-transform: uppercase;
+    letter-spacing: 1px;
+    margin-bottom: 5px;
+}
+
+.points-value {
+    font-size: 2em;
+    font-weight: bold;
+    color: #3498db;
+}
+
+.progress-section {
+    background: #34495e;
+    padding: 20px 40px;
+    border-bottom: 2px solid #2c3e50;
+}
+
+.progress-content {
+    max-width: 1200px;
+    margin: 0 auto;
+}
+
 .progress-label {
-    font-size: 1.3em;
-    color: #667eea;
+    font-size: 0.9em;
+    color: #ecf0f1;
     margin-bottom: 10px;
     font-weight: bold;
+    text-transform: uppercase;
+    letter-spacing: 1px;
 }
 
 .progress-bar-container {
     width: 100%;
-    height: 30px;
-    background: #e0e0e0;
-    border-radius: 15px;
+    height: 25px;
+    background: #2c3e50;
+    border: 1px solid #1a252f;
     overflow: hidden;
-    margin-bottom: 10px;
-    box-shadow: inset 0 2px 5px rgba(0, 0, 0, 0.1);
+    margin-bottom: 8px;
 }
 
 .progress-bar {
     height: 100%;
-    background: linear-gradient(90deg, #4facfe 0%, #00f2fe 100%);
+    background: #3498db;
     width: 0%;
     transition: width 0.5s ease;
-    border-radius: 15px;
-    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
 }
 
 .progress-text {
-    font-size: 1.1em;
-    color: #666;
+    font-size: 0.9em;
+    color: #bdc3c7;
     font-weight: bold;
 }
 
 .task-section {
-    margin-top: 30px;
+    padding: 30px 40px;
+    max-width: 1200px;
+    margin: 0 auto;
 }
 
 .chapter-description {
-    background: linear-gradient(135deg, #e8f5e9 0%, #fff3e0 100%);
-    padding: 20px;
-    border-radius: 15px;
-    margin-bottom: 25px;
-    font-size: 1.1em;
-    line-height: 1.6;
-    color: #555;
-    border-left: 4px solid #667eea;
-    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
+    background: #f8f9fa;
+    padding: 20px 25px;
+    margin-bottom: 30px;
+    font-size: 1em;
+    line-height: 1.7;
+    color: #2c3e50;
+    border-left: 4px solid #3498db;
+    border-top: 1px solid #e0e0e0;
+    border-right: 1px solid #e0e0e0;
+    border-bottom: 1px solid #e0e0e0;
+    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
 }
 
 .task-container {
     display: grid;
-    gap: 20px;
+    gap: 25px;
 }
 
 .task-card {
-    background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
-    padding: 25px;
-    border-radius: 15px;
-    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
-    transition: transform 0.2s, box-shadow 0.2s, opacity 0.5s ease, transform 0.5s ease;
+    background: #ffffff;
+    padding: 30px;
+    border: 2px solid #e0e0e0;
+    border-left: 4px solid #3498db;
+    transition: border-color 0.2s, box-shadow 0.2s;
     position: relative;
-    overflow: hidden;
+    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
 }
 
 .task-card:hover {
-    transform: translateY(-3px);
-    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
+    border-color: #3498db;
+    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
 }
 
 .task-card.confetti-animation {
@@ -184,24 +219,19 @@ h1 {
 
 @keyframes confettiFadeOut {
     0% {
-        transform: scale(1) rotate(0deg);
         opacity: 1;
     }
-    50% {
-        transform: scale(1.1) rotate(5deg);
-        opacity: 0.8;
-    }
     100% {
-        transform: scale(0) rotate(10deg);
         opacity: 0;
+        transform: translateY(-20px);
     }
 }
 
 .confetti {
     position: absolute;
-    width: 10px;
-    height: 10px;
-    background: #ffd700;
+    width: 8px;
+    height: 8px;
+    background: #3498db;
     animation: confettiFall linear forwards;
     z-index: 1000;
     pointer-events: none;
@@ -222,106 +252,112 @@ h1 {
     display: flex;
     justify-content: space-between;
     align-items: center;
-    margin-bottom: 15px;
+    margin-bottom: 20px;
+    padding-bottom: 15px;
+    border-bottom: 2px solid #e0e0e0;
 }
 
 .task-title {
-    font-size: 1.3em;
+    font-size: 1.1em;
     font-weight: bold;
-    color: #333;
+    color: #1a252f;
+    text-transform: uppercase;
+    letter-spacing: 1px;
 }
 
 .task-points {
-    background: #ffd700;
-    color: #333;
-    padding: 5px 15px;
-    border-radius: 20px;
+    background: #34495e;
+    color: #ecf0f1;
+    padding: 6px 15px;
+    border-radius: 2px;
     font-weight: bold;
-    font-size: 1.1em;
-    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
+    font-size: 0.9em;
+    border: 1px solid #2c3e50;
 }
 
 .task-question {
-    font-size: 1.5em;
-    text-align: center;
-    margin: 20px 0;
-    color: #333;
-    font-weight: bold;
+    font-size: 1.15em;
+    margin: 25px 0;
+    color: #2c3e50;
+    line-height: 1.7;
     white-space: pre-line;
+    font-weight: normal;
 }
 
 .task-input-group {
     display: flex;
-    gap: 10px;
+    gap: 15px;
     align-items: center;
-    justify-content: center;
-    margin-bottom: 15px;
+    justify-content: flex-start;
+    margin: 25px 0 15px 0;
+    padding-top: 20px;
+    border-top: 1px solid #e0e0e0;
 }
 
 .task-input {
-    font-size: 1.5em;
-    padding: 10px 15px;
-    border: 3px solid #667eea;
-    border-radius: 10px;
-    width: 120px;
+    font-size: 1.2em;
+    padding: 12px 18px;
+    border: 2px solid #bdc3c7;
+    border-radius: 2px;
+    width: 150px;
     text-align: center;
-    font-family: 'Comic Sans MS', cursive;
+    font-family: 'Arial', sans-serif;
     font-weight: bold;
+    background: #ffffff;
+    color: #1a1a1a;
 }
 
 .task-input:focus {
     outline: none;
-    border-color: #764ba2;
-    box-shadow: 0 0 10px rgba(102, 126, 234, 0.3);
+    border-color: #3498db;
+    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
 }
 
 .task-button {
-    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+    background: #3498db;
     color: white;
     border: none;
-    padding: 12px 25px;
-    font-size: 1.2em;
-    border-radius: 10px;
+    padding: 12px 30px;
+    font-size: 1em;
+    border-radius: 2px;
     cursor: pointer;
-    font-family: 'Comic Sans MS', cursive;
+    font-family: 'Arial', sans-serif;
     font-weight: bold;
-    transition: transform 0.2s, box-shadow 0.2s;
-    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
+    text-transform: uppercase;
+    letter-spacing: 1px;
+    transition: background-color 0.2s;
 }
 
 .task-button:hover {
-    transform: translateY(-2px);
-    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.3);
+    background: #2980b9;
 }
 
 .task-button:active {
-    transform: translateY(0);
+    background: #21618c;
 }
 
 .task-button:disabled {
-    background: #ccc;
+    background: #95a5a6;
     cursor: not-allowed;
-    transform: none;
 }
 
 .task-status {
-    text-align: center;
-    font-size: 1.1em;
+    margin-top: 15px;
+    font-size: 1em;
     font-weight: bold;
-    margin-top: 10px;
     min-height: 25px;
 }
 
 .task-status.success {
-    color: #4caf50;
+    color: #27ae60;
 }
 
 .task-status.error {
-    color: #f44336;
+    color: #e74c3c;
 }
 
 .task-status.completed {
-    color: #ff9800;
+    color: #f39c12;
 }
 
 .message {
@@ -329,13 +365,14 @@ h1 {
     top: 20px;
     right: 20px;
     padding: 15px 25px;
-    border-radius: 10px;
+    border-radius: 2px;
     font-weight: bold;
-    font-size: 1.2em;
-    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
+    font-size: 1em;
+    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
     transform: translateX(400px);
     transition: transform 0.3s ease;
     z-index: 1000;
+    border: 2px solid;
 }
 
 .message.show {
@@ -343,70 +380,81 @@ h1 {
 }
 
 .message.success {
-    background: #4caf50;
+    background: #27ae60;
     color: white;
+    border-color: #229954;
 }
 
 .message.error {
-    background: #f44336;
+    background: #e74c3c;
     color: white;
+    border-color: #c0392b;
 }
 
 @media (max-width: 900px) {
     .app-wrapper {
         flex-direction: column;
-        padding: 10px;
     }
     
     .sidebar {
         width: 100%;
         position: relative;
-        top: 0;
-        max-height: none;
-        display: flex;
-        gap: 10px;
-        overflow-x: auto;
-        overflow-y: hidden;
-        padding: 15px;
+        height: auto;
+        max-height: 300px;
+        border-right: none;
+        border-bottom: 3px solid #1a252f;
     }
     
     .sidebar-item {
-        min-width: 200px;
-        margin-bottom: 0;
+        border-bottom: 1px solid #2c3e50;
+    }
+    
+    .header-content {
+        flex-direction: column;
+        gap: 20px;
+        align-items: flex-start;
     }
 }
 
 @media (max-width: 600px) {
     .container {
+        padding: 0;
+    }
+    
+    header {
         padding: 20px;
     }
     
     h1 {
-        font-size: 2em;
+        font-size: 1.4em;
     }
     
     .points-value {
-        font-size: 2.5em;
+        font-size: 1.5em;
+    }
+    
+    .task-section {
+        padding: 20px;
     }
     
     .task-input-group {
         flex-direction: column;
+        align-items: stretch;
+    }
+    
+    .task-input {
+        width: 100%;
     }
     
     .task-button {
         width: 100%;
     }
     
-    .sidebar {
-        padding: 10px;
-    }
-    
     .sidebar-item {
-        min-width: 180px;
-        padding: 12px;
+        padding: 12px 15px;
     }
     
     .sidebar-item-title {
-        font-size: 1em;
+        font-size: 0.9em;
     }
 }