diff --git a/assets/css/main.css b/assets/css/main.css
index 3dad5fc..93853fd 100644
--- a/assets/css/main.css
+++ b/assets/css/main.css
@@ -1,3 +1,25 @@
+/* ========================
+   Farbvariablen
+   ======================== */
+:root {
+    --color-background: #f8f9fa;
+    --color-text: #191A23;
+    --color-accent: #BBE04C;
+    --color-primary-button-dark: #191A23;
+    --color-primary-button-light: #FFFFFF;
+    --color-link: #405C00;
+    --color-error: #d9534f;
+    --color-offwhite: #F3F3F3;
+    --color-offblack: #1D1F29
+}
+
+.dark {
+    --color-background: #191A23;
+    --color-text: #F2F2F2;
+    --color-text-dark: #191A23;
+    --color-link: #BBE04C;
+}
+
 /* ========================
    Allgemein
    ======================== */
@@ -7,10 +29,10 @@ html, body {
 
 body {
     font-family: 'Cairo', sans-serif;
-    background-color: #f8f9fa;
+    background-color: var(--color-background);
     margin: 0;
     padding: 0;
-    color: #191A23;
+    color: var(--color-text);
     display: flex;
     flex-direction: column;
     justify-content: flex-start;
@@ -26,7 +48,7 @@ h1, h2, h3, h4, h5 {
     font-weight: 500;
     margin-top: 1rem;
     margin-bottom: 0.5rem;
-    color: #1a1a1a;
+    color: var(--color-text);
     text-align: left;
 }
 
@@ -36,17 +58,17 @@ p {
 }
 
 .container {
+    background-color: var(--color-background);
     width: 100%;
     max-width: 1200px;
     margin: 0 auto;
-    padding: 0 15px;
 }
 
 /* ========================
    Navbar
    ======================== */
 .navbar {
-    padding: 15px 0;
+    padding: 1rem 0;
     top: 0;
     left: 0;
     width: 100%;
@@ -58,12 +80,18 @@ p {
 }
 
 .navbar-brand {
+    color: var(--color-text);
     font-family: 'Exo 2', sans-serif;
     font-size: 1.5rem;
     font-weight: bold;
 }
 
+.navbar-brand:hover {
+    color: var(--color-accent);
+}
+
 .navbar-nav .nav-link {
+    color: var(--color-text);
     font-size: 1.1rem;
     margin-right: 10px;
     transition: color 0.3s ease-in-out;
@@ -91,9 +119,58 @@ li .dropdown-item-mobile {
     margin-top: 0;
 }
 
+.dark .show-on-hover:hover > .dropdown-menu {
+    background-color: var(--color-offblack);
+}
+
 .dropdown-menu .dropdown-item:active {
     background-color: #e0e0e0;
-    color: #191A23;
+    color: var(--color-text);
+}
+
+.dropdown-menu .dropdown-item {
+    padding: 0.3rem 0 0.3rem 1rem;
+}
+
+.dark .dropdown-menu .dropdown-item {
+    color: var(--color-text);
+}
+
+.dark .dropdown-menu .dropdown-item:active {
+    background-color: var(--color-offblack);
+    color: var(--color-text);
+}
+
+.dark .dropdown-menu .dropdown-item:hover {
+    background-color: var(--color-accent);
+    color: var(--color-text-dark);
+}
+
+#theme-switch {
+    height: 2.3rem;
+    width: 2.3rem;
+    padding: 0;
+    border: none;
+    border-radius: 50%;
+    background-color: transparent;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    appearance: none;
+}
+
+#theme-switch img#light-icon {
+    display: none;
+}
+#theme-switch img#dark-icon {
+    display: inline;
+}
+
+.dark #theme-switch img#light-icon {
+    display: inline;
+}
+.dark #theme-switch img#dark-icon {
+    display: none;
 }
 
 /* ========================
@@ -117,7 +194,7 @@ li .dropdown-item-mobile {
 .hero-section p {
     margin-bottom: 0.5rem;
     font-size: 1.25rem;
-    color: #191A23;
+    color: var(--color-text);
     max-width: 35rem;
     margin-left: auto;
     margin-right: auto;
@@ -126,41 +203,54 @@ li .dropdown-item-mobile {
 /* ========================
    Button
    ======================== */
-.btn-primary-dark {
-    background-color: #191A23;
-    color: #ffffff;
+.btn-primary {
+    border: 1px solid var(--color-primary-button-dark);
+    background-color: var(--color-primary-button-dark);
+    color: var(--color-primary-button-light);
 }
 
-.btn-primary-dark:hover {
-    color: #191A23;
+.btn-primary:hover {
+    color: var(--color-primary-button-dark);
     background-color: transparent;
-    border-color: #191A23;
-    box-shadow: 0 4px 0 0 #191A23;
+    border: 1px solid var(--color-primary-button-dark);
+    box-shadow: 0 4px 0 0 var(--color-primary-button-dark);
 }
 
-.btn-primary-light {
+.dark .btn-primary {
+    border: 1px solid var(--color-accent);
+    background-color: var(--color-accent);
+    color: var(--color-text-dark);
+}
+
+.dark .btn-primary:hover {
+    color: var(--color-text);
     background-color: transparent;
-    color: #191A23;
-    border-color: #191A23;
+    border: 1px solid var(--color-accent);
+    box-shadow: 0 4px 0 0 var(--color-accent);
 }
 
-.btn-primary-light:hover {
-    color: #191A23;
+.btn-secondary {
     background-color: transparent;
-    border-color: #191A23;
-    box-shadow: 0 4px 0 0 #191A23;
+    color: var(--color-primary-button-dark);
+    border: 1px solid var(--color-primary-button-dark);
 }
 
-.btn-primary-green {
-    background-color: #BBE04C;
-    color: #191A23;
-}
-
-.btn-primary-green:hover {
-    color: #191A23;
+.btn-secondary:hover {
+    color: var(--color-primary-button-dark);
     background-color: transparent;
-    border-color: #BBE04C;
-    box-shadow: 0 4px 0 0 #BBE04C;
+    border-color: var(--color-primary-button-dark);
+    box-shadow: 0 4px 0 0 var(--color-primary-button-dark);
+}
+
+.dark .btn-secondary {
+    color: var(--color-primary-button-light);
+    border: 1px solid var(--color-primary-button-light);
+}
+
+.dark .btn-secondary:hover {
+    color: var(--color-primary-button-light);
+    border-color: var(--color-primary-button-light);
+    box-shadow: 0 4px 0 0 var(--color-primary-button-light);
 }
 
 /* ========================
@@ -173,7 +263,7 @@ li .dropdown-item-mobile {
     hyphens: auto;
     text-align: left;
     line-height: 1.8;
-    color: #191A23;
+    color: var(--color-text);
 }
 
 #markdown h1 {
@@ -181,49 +271,58 @@ li .dropdown-item-mobile {
     margin-top: 0;
     margin-bottom: 2rem;
     text-align: left;
-    color: #191A23;
-    background-color: #BBE04C;
+    color: var(--color-text);
+    background-color: var(--color-accent);
     border-radius: 8px;
     padding: 5px 10px;
     display: inline-block;
-    box-shadow: 0 4px 0 0 #191A23;
+    box-shadow: 0 4px 0 0 var(--color-text);
+}
+
+.dark #markdown h1 {
+    color: var(--color-text-dark);
+    box-shadow: 0 4px 0 0 var(--color-offblack);
 }
 
 #markdown h1::before {
     content: "// ";
-    color: #191A23;
+    color: var(--color-text);
     font-weight: bold;
 }
 
+.dark #markdown h1::before {
+    color: var(--color-text-dark);
+}
+
 #markdown h2 {
     font-size: 2rem;
-    color: #191A23;
+    color: var(--color-text);
 }
 
 #markdown h3 {
     font-size: 1.5rem;
-    color: #191A23;
+    color: var(--color-text);
 }
 
 #markdown h4 {
     font-size: 1.25rem;
-    color: #191A23;
+    color: var(--color-text);
 }
 
 #markdown h5 {
     font-size: 1.1rem;
-    color: #191A23;
+    color: var(--color-text);
 }
 
 #markdown h6 {
     font-size: 1rem;
-    color: #191A23;
+    color: var(--color-text);
 }
 
 #markdown p,
 #markdown li {
     font-size: 1.1rem;
-    color: #191A23;
+    color: var(--color-text);
 }
 
 #markdown ul, #markdown ol {
@@ -236,11 +335,17 @@ li .dropdown-item-mobile {
     border-spacing: 0;
     margin-bottom: 1.5rem;
     font-size: 1.1rem;
-    color: #191A23;
-    border: 1px solid #191A23;
+    color: var(--color-text);
+    border: 1px solid var(--color-text);
     border-radius: 10px;
     overflow: hidden;
-    box-shadow: 0 4px 0 0 #191A23;
+    box-shadow: 0 4px 0 0 var(--color-text);
+}
+
+.dark #markdown table {
+    color: var(--color-text);
+    border: 1px solid var(--color-offwhite);
+    box-shadow: 0 4px 0 0 var(--color-offwhite);
 }
 
 #markdown th,
@@ -251,36 +356,60 @@ li .dropdown-item-mobile {
     border-radius: 0;
 }
 
+.dark #markdown th,
+#markdown td {
+    border: 1px solid var(--color-offwhite);
+    padding: 12px 15px;
+    text-align: left;
+    border-radius: 0;
+}
+
 #markdown th {
     background-color: #f2f2f2;
-    color: #191A23;
+    color: var(--color-text);
+    font-weight: bolder;
+}
+
+.dark #markdown th {
+    background-color: var(--color-offblack);
+    color: var(--color-text);
     font-weight: bolder;
 }
 
 #markdown blockquote {
-    background-color: #F3F3F3;
-    padding: 20px;
+    background-color: var(--color-offwhite);
+    padding: 20px 20px 7px 20px;
     margin-bottom: 20px;
-    color: #191A23;
-    border: 1px solid #191A23;
+    color: var(--color-text);
+    border: 1px solid var(--color-text);
     border-radius: 10px;
-    box-shadow: 0 4px 0 0 #191A23;
+    box-shadow: 0 4px 0 0 var(--color-text);
+}
+
+.dark #markdown blockquote {
+    background-color: var(--color-offblack);
+    padding: 20px 20px 7px 20px;
+    margin-bottom: 20px;
+    color: var(--color-text);
+    border: 1px solid var(--color-offwhite);
+    border-radius: 10px;
+    box-shadow: 0 4px 0 0 var(--color-offwhite);
 }
 
 #markdown a {
-    color: #6A9500;
+    color: var(--color-link);
     text-decoration: none;
     transition: color 0.3s;
 }
 
 #markdown a:hover {
-    color: #6A9500;
+    color: var(--color-link);
     text-decoration: underline;
 }
 
 #markdown code {
     background-color: #f2f2f2;
-    color: #191A23;
+    color: var(--color-text);
     padding: 0.2rem 0.4rem;
     border-radius: 4px;
     font-size: 1.05rem;
@@ -321,14 +450,14 @@ li .dropdown-item-mobile {
 }
 
 .footer-nav a {
-    color: #191A23;
+    color: var(--color-text);
     text-decoration: none;
     transition: color 0.3s ease;
 }
 
 .footer-nav a:hover,
 .footer-nav a:focus {
-    color: #191A23;
+    color: var(--color-text);
     text-decoration: underline;
     outline: none;
 }
@@ -337,7 +466,6 @@ li .dropdown-item-mobile {
    404 Error Page
    ======================== */
 .page-not-found {
-    margin-top: 10rem;
     height: 100%;
     display: flex;
     flex-direction: column;
@@ -350,12 +478,12 @@ li .dropdown-item-mobile {
 .page-not-found .error-code {
     font-size: 6rem;
     font-weight: bold;
-    color: #d9534f;
+    color: var(--color-error);
 }
 
 .page-not-found .error-message {
     font-size: 1.25rem;
-    color: #191A23;
+    color: var(--color-text);
 }
 
 
@@ -368,7 +496,6 @@ li .dropdown-item-mobile {
     }
 }
 
-
 @media (min-width: 992px) {
     .dropdown-item-mobile {
         display: none !important;
@@ -376,8 +503,16 @@ li .dropdown-item-mobile {
 }
 
 @media (max-width: 576px) {
+    .hero-section h1 {
+        font-size: 2rem;
+    }
+
+    .hero-section p {
+        font-size: 1rem;
+    }
+
     #markdown {
-        padding: 2rem 0 0 0;
+        padding: 1rem 0 0 0;
     }
 
     #markdown h1 {
diff --git a/assets/images/hero-image.jpg b/assets/images/hero-image.jpg
new file mode 100644
index 0000000..0d6824b
Binary files /dev/null and b/assets/images/hero-image.jpg differ
diff --git a/assets/images/hero-image.png b/assets/images/hero-image.png
deleted file mode 100644
index db501a5..0000000
Binary files a/assets/images/hero-image.png and /dev/null differ
diff --git a/assets/js/main.js b/assets/js/main.js
index e69de29..e434c4b 100644
--- a/assets/js/main.js
+++ b/assets/js/main.js
@@ -0,0 +1,50 @@
+document.addEventListener("DOMContentLoaded", () => {
+    const themeSwitch = document.getElementById("theme-switch");
+    const prefersDarkScheme = window.matchMedia("(prefers-color-scheme: dark)");
+
+    const applyTheme = (theme) => {
+        document.documentElement.classList.toggle("dark", theme === "dark");
+    };
+
+    const getStoredTheme = () => localStorage.getItem("theme");
+    const setStoredTheme = (theme) => localStorage.setItem("theme", theme);
+
+    // Initial load
+    const savedTheme = getStoredTheme();
+    if (savedTheme) {
+        applyTheme(savedTheme);
+    } else {
+        applyTheme(prefersDarkScheme.matches ? "dark" : "light");
+    }
+
+    // system changes
+    prefersDarkScheme.addEventListener("change", (e) => {
+        const saved = getStoredTheme();
+        if (!saved) {
+            applyTheme(e.matches ? "dark" : "light");
+        }
+    });
+
+    // toggle handler
+    themeSwitch.addEventListener("click", () => {
+        const currentTheme = document.documentElement.classList.contains("dark") ? "dark" : "light";
+        const newTheme = currentTheme === "dark" ? "light" : "dark";
+        applyTheme(newTheme);
+        setStoredTheme(newTheme);
+    });
+
+
+    const updateBodyThemeAttr = () => {
+        const current = document.documentElement.classList.contains("dark") ? "dark" : "light";
+        document.body.setAttribute("data-theme", current);
+    };
+    updateBodyThemeAttr();
+
+    // update on change
+    const observer = new MutationObserver(updateBodyThemeAttr);
+    observer.observe(document.documentElement, { attributes: true, attributeFilter: ["class"] });
+
+    prefersDarkScheme.addEventListener("change", () => {
+        updateBodyThemeAttr();
+    });
+});
\ No newline at end of file
diff --git a/layouts/_default/baseof.html b/layouts/_default/baseof.html
index f6ae23f..72910fe 100644
--- a/layouts/_default/baseof.html
+++ b/layouts/_default/baseof.html
@@ -11,9 +11,7 @@
     </div>
   </header>
   <main>
-    <div class="container">
-      {{ block "main" . }}{{ end }}
-    </div>
+    {{ block "main" . }}{{ end }}
   </main>
   <footer>
     <div class="container">
diff --git a/layouts/_default/single.html b/layouts/_default/single.html
index d9c102e..af9bd61 100644
--- a/layouts/_default/single.html
+++ b/layouts/_default/single.html
@@ -1,5 +1,7 @@
 {{ define "main" }}
-  <div id="markdown">
-    {{ .Content }}
+  <div class="container">
+    <div id="markdown">
+      {{ .Content }}
+    </div>
   </div>
 {{ end }}
\ No newline at end of file
diff --git a/layouts/_partials/head/js.html b/layouts/_partials/head/js.html
index 16ffbed..0da46ed 100644
--- a/layouts/_partials/head/js.html
+++ b/layouts/_partials/head/js.html
@@ -9,7 +9,7 @@
       <script src="{{ .RelPermalink }}"></script>
     {{- else }}
       {{- with . | fingerprint }}
-        <script src="{{ .RelPermalink }}" integrity="{{ .Data.Integrity }}" crossorigin="anonymous"></script>
+        <script src="{{ .RelPermalink }}" integrity="{{ .Data.Integrity }}" defer crossorigin="anonymous"></script>
       {{- end }}
     {{- end }}
   {{- end }}
diff --git a/layouts/_partials/hero.html b/layouts/_partials/hero.html
index 44e1f6f..cd79b65 100644
--- a/layouts/_partials/hero.html
+++ b/layouts/_partials/hero.html
@@ -1,12 +1,12 @@
-<section class="py-5 bg-light hero-section">
+<section class="py-5 hero-section">
     <div class="container">
         <div class="row align-items-center">
             <div class="col-md-12 text-center mb-4 mb-md-0">
                 <h1 class="display-5 fw-bold text-center">Willkommen auf der Website des FSR Informatik</h1>
-                <p class="lead text-muted text-center">Gemeinsam stark im Studium – dein Fachschaftsrat steht für Austausch, Unterstützung und Mitgestaltung.</p>
+                <p class="lead text-center">Gemeinsam stark im Studium – dein Fachschaftsrat steht für Austausch, Unterstützung und Mitgestaltung.</p>
                 <div class="d-flex justify-content-center gap-4 mt-3">
-                    <a href="{{ "/about" | relURL }}" class="btn btn-primary-dark btn-lg">mehr erfahren</a>
-                    <a href="{{ "/kontakt" | relURL }}" class="btn btn-primary-light btn-lg">kontaktieren</a>
+                    <a href="{{ "/about" | relURL }}" class="btn btn-primary btn-lg">mehr erfahren</a>
+                    <a href="{{ "/kontakt" | relURL }}" class="btn btn-secondary btn-lg">kontaktieren</a>
                 </div>
             </div>
         </div>
diff --git a/layouts/_partials/nav.html b/layouts/_partials/nav.html
index ed691e1..614c270 100644
--- a/layouts/_partials/nav.html
+++ b/layouts/_partials/nav.html
@@ -1,4 +1,4 @@
-<nav class="navbar navbar-expand-lg navbar-light bg-light">
+<nav class="navbar navbar-expand-lg">
     <div class="container-fluid">
         <a class="navbar-brand d-flex align-items-center" href="{{ "/" | relURL }}">
             <img src="{{ "images/logo.svg" | relURL }}" alt="iFSR Logo" height="50" class="me-2">
@@ -37,5 +37,12 @@
                 {{ end }}
             </ul>
         </div>
+        <div class="d-none d-lg-flex ms-3">
+            <button id="theme-switch" class="btn btn-link nav-link">
+                <img id="light-icon" src="{{ "/icons/light.svg" | relURL }}" alt="Light Mode Icon" class="theme-icon">
+                <img id="dark-icon" src="{{ "/icons/dark.svg" | relURL }}" alt="Dark Mode Icon" class="theme-icon">
+            </button>
+        </div>
+
     </div>
 </nav>
\ No newline at end of file
diff --git a/static/icons/dark.svg b/static/icons/dark.svg
new file mode 100644
index 0000000..c6a2aed
--- /dev/null
+++ b/static/icons/dark.svg
@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 -960 960 960" width="24px" fill="#191A23">
+    <path d="M480-120q-150 0-255-105T120-480q0-150 105-255t255-105q14 0 27.5 1t26.5 3q-41 29-65.5 75.5T444-660q0 90 63 153t153 63q55 0 101-24.5t75-65.5q2 13 3 26.5t1 27.5q0 150-105 255T480-120Z"/>
+</svg>
\ No newline at end of file
diff --git a/static/icons/light.svg b/static/icons/light.svg
new file mode 100644
index 0000000..f52e723
--- /dev/null
+++ b/static/icons/light.svg
@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 -960 960 960" width="24px" fill="#FFFFFF">
+    <path d="M480-280q-83 0-141.5-58.5T280-480q0-83 58.5-141.5T480-680q83 0 141.5 58.5T680-480q0 83-58.5 141.5T480-280ZM200-440H40v-80h160v80Zm720 0H760v-80h160v80ZM440-760v-160h80v160h-80Zm0 720v-160h80v160h-80ZM256-650l-101-97 57-59 96 100-52 56Zm492 496-97-101 53-55 101 97-57 59Zm-98-550 97-101 59 57-100 96-56-52ZM154-212l101-97 55 53-97 101-59-57Z"/>
+</svg>
\ No newline at end of file