diff --git a/app/static/css/style.css b/app/static/css/style.css
index 48c1f43..7e69db5 100755
--- a/app/static/css/style.css
+++ b/app/static/css/style.css
@@ -302,11 +302,14 @@ body {
     padding: 16px 20px;
     box-shadow: 0 4px 12px rgba(0, 0, 0, 0.35);
     z-index: 2;
+    /* In closed state: 100% completely hidden, invisible, non-rendered */
+    visibility: hidden;
     opacity: 0;
-    transform: translateY(40px) scale(0.92);
+    transform: translateY(50px) scale(0.92);
     pointer-events: none;
     transition: transform 0.9s cubic-bezier(0.2, 0.85, 0.25, 1) 0.35s, 
                 opacity 0.6s ease 0.35s, 
+                visibility 0.6s ease 0.35s,
                 box-shadow 0.8s ease;
     overflow-y: auto;
     text-align: center;
@@ -325,25 +328,54 @@ body {
     border-radius: 4px;
 }
 
-/* Front Pocket of envelope (covers the lower portion of the letter) */
-.envelope-front-pocket {
+/* =========================================
+   FOUR-FLAP REALISTIC CLOSED ENVELOPE SYSTEM
+   Flaps: Left, Right, Bottom, and Top Flap
+   ========================================= */
+.envelope-flap {
     position: absolute;
     inset: 0;
-    border-radius: 6px;
+    pointer-events: none;
+}
+
+/* Left Triangular Flap */
+.envelope-flap.flap-left {
     background-color: #ebdcb9;
     background-image: 
-        radial-gradient(ellipse at 50% 65%, rgba(255, 255, 255, 0.25) 0%, rgba(130, 95, 45, 0.2) 100%),
+        radial-gradient(ellipse at 0% 50%, rgba(255, 255, 255, 0.22) 0%, rgba(130, 95, 45, 0.22) 100%),
         url('/static/img/parchment_texture.jpg');
     background-size: cover;
-    clip-path: polygon(0 16%, 50% 50%, 100% 16%, 100% 100%, 0 100%);
+    clip-path: polygon(0 0, 50% 50%, 0 100%);
+    z-index: 3;
+    filter: drop-shadow(2px 0 4px rgba(60, 40, 15, 0.25));
+}
+
+/* Right Triangular Flap */
+.envelope-flap.flap-right {
+    background-color: #ebdcb9;
+    background-image: 
+        radial-gradient(ellipse at 100% 50%, rgba(255, 255, 255, 0.22) 0%, rgba(130, 95, 45, 0.22) 100%),
+        url('/static/img/parchment_texture.jpg');
+    background-size: cover;
+    clip-path: polygon(100% 0, 50% 50%, 100% 100%);
+    z-index: 3;
+    filter: drop-shadow(-2px 0 4px rgba(60, 40, 15, 0.25));
+}
+
+/* Bottom Flap (Folds up from bottom, overlaps left/right flaps, holds the address) */
+.envelope-flap.flap-bottom {
+    background-color: #dfcd9f;
+    background-image: 
+        radial-gradient(ellipse at 50% 80%, rgba(255, 255, 255, 0.28) 0%, rgba(130, 95, 45, 0.25) 100%),
+        url('/static/img/parchment_texture.jpg');
+    background-size: cover;
+    clip-path: polygon(0 100%, 50% 48%, 100% 100%);
     z-index: 4;
-    border: 2px solid #8e6c43;
-    filter: drop-shadow(0 -3px 6px rgba(60, 40, 15, 0.3));
+    filter: drop-shadow(0 -4px 6px rgba(50, 35, 10, 0.35));
     display: flex;
     align-items: flex-end;
     justify-content: center;
-    padding-bottom: 22px;
-    pointer-events: none;
+    padding-bottom: 20px;
 }
 
 .envelope-sketch-border {
@@ -357,7 +389,7 @@ body {
     pointer-events: none;
 }
 
-/* Handwritten Address in Emerald Ink on Envelope Front */
+/* Handwritten Address in Emerald Ink on Envelope Bottom Flap */
 .envelope-address-block {
     position: relative;
     z-index: 5;
@@ -366,61 +398,62 @@ body {
     color: #0d3820; /* Authentic Hogwarts Emerald Ink */
     padding: 0 15px;
     text-shadow: 0 0 1px rgba(13, 56, 32, 0.35);
+    margin-bottom: 2px;
 }
 
 .addr-school {
-    font-size: clamp(0.92rem, 3.2vw, 1.15rem);
+    font-size: clamp(0.85rem, 2.9vw, 1.08rem);
     font-weight: 700;
     color: #082816;
-    margin-bottom: 2px;
+    margin-bottom: 1px;
 }
 
 .addr-recipient {
-    font-size: clamp(1.15rem, 3.8vw, 1.4rem);
+    font-size: clamp(1.05rem, 3.4vw, 1.28rem);
     font-weight: 700;
     color: #0b3a20;
-    margin-bottom: 2px;
+    margin-bottom: 1px;
 }
 
 .addr-location {
-    font-size: clamp(0.85rem, 2.8vw, 1.02rem);
+    font-size: clamp(0.8rem, 2.5vw, 0.96rem);
     font-style: italic;
     color: #1e4530;
 }
 
-/* Top Triangular Flap (folds down over the pocket) */
-.envelope-closing-flap {
+/* Top Closing Flap (Folds down from top, overlaps all flaps, sealed by wax seal) */
+.envelope-closing-flap.flap-top {
     position: absolute;
     top: 0;
     left: 0;
     width: 100%;
     height: 100%;
-    background-color: #dfcd9f;
+    background-color: #e5d4a6;
     background-image: 
-        radial-gradient(ellipse at 50% 25%, rgba(255, 255, 255, 0.3) 0%, rgba(130, 95, 45, 0.25) 100%),
+        radial-gradient(ellipse at 50% 20%, rgba(255, 255, 255, 0.35) 0%, rgba(130, 95, 45, 0.25) 100%),
         url('/static/img/parchment_texture.jpg');
     background-size: cover;
-    clip-path: polygon(0 0, 100% 0, 50% 57%);
+    clip-path: polygon(0 0, 100% 0, 50% 54%);
     transform-origin: top center;
     transform-style: preserve-3d;
-    transition: transform 0.75s cubic-bezier(0.4, 0, 0.2, 1);
+    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
     z-index: 6;
     border-top: 2px solid #8e6c43;
-    filter: drop-shadow(0 5px 8px rgba(50, 35, 10, 0.5));
+    filter: drop-shadow(0 6px 9px rgba(45, 30, 10, 0.55));
 }
 
 .flap-sketch-line {
     position: absolute;
     inset: 4px;
-    clip-path: polygon(2% 2%, 98% 2%, 50% 54%);
+    clip-path: polygon(2% 2%, 98% 2%, 50% 52%);
     border-top: 1px dashed rgba(120, 85, 45, 0.4);
     pointer-events: none;
 }
 
-/* Sketched Wax Seal placed right over the flap tip */
+/* Sketched Wax Seal placed right over the flap intersection in the center */
 .sketched-wax-seal {
     position: absolute;
-    top: 55%;
+    top: 50%;
     left: 50%;
     transform: translate(-50%, -50%) rotate(-3deg);
     width: 74px;
@@ -430,8 +463,8 @@ body {
     z-index: 7;
     transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.3s ease, opacity 0.4s ease;
     box-shadow: 
-        0 8px 20px rgba(0, 0, 0, 0.7),
-        0 2px 5px rgba(0, 0, 0, 0.45);
+        0 8px 22px rgba(0, 0, 0, 0.75),
+        0 2px 6px rgba(0, 0, 0, 0.45);
 }
 
 .sketched-wax-seal:hover {
@@ -480,13 +513,14 @@ body {
     pointer-events: none;
 }
 
-.envelope-opened .envelope-closing-flap {
+.envelope-opened .envelope-closing-flap.flap-top {
     transform: rotateX(180deg);
     z-index: 1;
     filter: drop-shadow(0 -4px 6px rgba(50, 35, 10, 0.4));
 }
 
 .envelope-opened .letter-sheet {
+    visibility: visible;
     opacity: 1;
     pointer-events: auto;
     transform: translateY(-145px) scale(1.02);
@@ -738,7 +772,7 @@ body {
     .sketched-wax-seal {
         width: 62px;
         height: 62px;
-        top: 55%;
+        top: 50%;
     }
     .letter-sheet {
         top: 10px;
@@ -756,8 +790,8 @@ body {
         line-height: 1.42;
         margin-bottom: 6px;
     }
-    .envelope-front-pocket {
-        padding-bottom: 14px;
+    .envelope-flap.flap-bottom {
+        padding-bottom: 12px;
     }
     .btn-launch-quiz {
         padding: 12px 20px;
diff --git a/app/templates/base.html b/app/templates/base.html
index 85463cd..c1f0629 100755
--- a/app/templates/base.html
+++ b/app/templates/base.html
@@ -8,7 +8,7 @@
     <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=Caveat:wght@500;700&family=Marck+Script&family=MedievalSharp&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/static/css/style.css?v=2.6">
+    <link rel="stylesheet" href="/static/css/style.css?v=2.7">
     {% block head %}{% endblock %}
 </head>
 <body>
diff --git a/app/templates/index.html b/app/templates/index.html
index 04215cb..31bb7d1 100755
--- a/app/templates/index.html
+++ b/app/templates/index.html
@@ -55,8 +55,14 @@
                     </footer>
                 </div>
 
-                <!-- Vordere Umschlagtasche mit handschriftlicher Smaragd-Anschrift -->
-                <div class="envelope-front-pocket">
+                <!-- Linke Klappe des Umschlags -->
+                <div class="envelope-flap flap-left"></div>
+
+                <!-- Rechte Klappe des Umschlags -->
+                <div class="envelope-flap flap-right"></div>
+
+                <!-- Untere Klappe des Umschlags mit handschriftlicher Smaragd-Anschrift -->
+                <div class="envelope-flap flap-bottom">
                     <div class="envelope-sketch-border"></div>
                     <div class="envelope-address-block">
                         <p class="addr-line addr-school" id="envelopeLetter">Hogwarts-Schule für Hexerei und Zauberei</p>
@@ -65,8 +71,8 @@
                     </div>
                 </div>
 
-                <!-- Obere Klappe des Umschlags (überdeckt die Tasche und wird vom Siegel gehalten) -->
-                <div class="envelope-closing-flap">
+                <!-- Obere Klappe des Umschlags (überdeckt alle Falten und wird vom Siegel gehalten) -->
+                <div class="envelope-closing-flap flap-top" id="envelopeFlap">
                     <div class="flap-sketch-line"></div>
                 </div>
 
@@ -183,5 +189,5 @@
 {% endblock %}
 
 {% block scripts %}
-<script src="/static/js/quiz.js?v=2.6"></script>
+<script src="/static/js/quiz.js?v=2.7"></script>
 {% endblock %}