diff --git a/.gitignore b/.gitignore
index 44620bd..1175977 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,4 @@
 icons/action.xcf
 TODO.txt
-
-*.crx
-
-*.pem
+.releases
+chrome/icons/icon-128\.png
diff --git a/firefox/background.js b/firefox/background.js
new file mode 100644
index 0000000..2769532
--- /dev/null
+++ b/firefox/background.js
@@ -0,0 +1,61 @@
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 17):
+ * <saphareas@gmail.com> wrote this file.  As long as you retain this notice you
+ * can use this stuff for any non-commercial purposes. If we meet some day,
+ * and you think this stuff is worth it, you can buy me a beer in return.
+ *                                                                Fabian Große
+ * ----------------------------------------------------------------------------
+ */
+
+var tabID; //global ist nicht schön
+
+function init() {
+    var getStorage = browser.storage.local.get(null,
+        function getStorageCallback(items){
+            if ("isDark" in items) {
+                if (items["isDark"]) {
+                    _toggleDarkModeHelper();
+                }
+            }
+            else {
+                browser.storage.local.set({isDark: false});
+            }
+        }
+    )
+}
+
+//Zeige die Page Action für den Tab, aus dem eine Message kam (pietsmiet.de)
+function showPageAction(request, sender) {
+    tabID = sender.tab.id;
+    browser.pageAction.show(tabID);
+    init();
+}
+
+function toggleDarkMode(actionTitle) {
+    if (actionTitle == "Abdunkeln") {
+        browser.tabs.sendMessage(tabID, "toDark"); //benachrichtige Content-Script, das Theme zu dunkel zu wechseln
+        browser.pageAction.setTitle({tabId: tabID, title: "Zurück zu Normal"});
+        browser.pageAction.setIcon({tabId: tabID, path: {
+            19: "icons/action-19.png",
+            38: "icons/action-38.png"
+        }});
+    }
+    else {
+        browser.tabs.sendMessage(tabID, "reset"); //benachrichtige Content-Script, das Theme zu normal zu wechseln
+        browser.pageAction.setTitle({tabId: tabID, title: "Abdunkeln"});
+        browser.pageAction.setIcon({tabId: tabID, path: {
+            19: "icons/action-off-19.png",
+            38: "icons/action-off-38.png"
+        }});
+    }
+}
+
+//Helper-Funktion, weil getTitle unbedingt einen Callback haben muss o.O
+function _toggleDarkModeHelper() {
+    //ruft toggleDarkMode auf und übergibt den aktuellen Action Title
+    browser.pageAction.getTitle({tabId: tabID}, toggleDarkMode);
+}
+
+browser.runtime.onMessage.addListener(showPageAction); //Sobald das Background-Script eine Message erhält, showPageAction ausführen
+browser.pageAction.onClicked.addListener(_toggleDarkModeHelper); //sobald auf die Page Action geklickt wurde, führe _toggleDarkModeHelper aus
diff --git a/firefox/content.js b/firefox/content.js
new file mode 100644
index 0000000..22ba248
--- /dev/null
+++ b/firefox/content.js
@@ -0,0 +1,36 @@
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 17):
+ * <saphareas@gmail.com> wrote this file.  As long as you retain this notice you
+ * can use this stuff for any non-commercial purposes. If we meet some day,
+ * and you think this stuff is worth it, you can buy me a beer in return.
+ *                                                                Fabian Große
+ * ----------------------------------------------------------------------------
+ */
+
+const CSS_FILE = browser.runtime.getURL("darken_ps.css"); //Voll-qualifizierter Pfad zur "dunklen" CSS-Datei
+
+function onToggleMode(request, sender) {
+    if (request == "toDark") { //Wenn auf dunkel gewechselt werden soll
+        var element = document.createElement("link");
+        element.setAttribute("id", "darkmode"); //id, um es später wieder zu finden
+        element.setAttribute("rel", "stylesheet");
+        element.setAttribute("type", "text/css");
+        element.setAttribute("href", CSS_FILE);
+        document.getElementsByTagName("head")[0].appendChild(element); //hänge an den Head an
+        browser.storage.local.set({isDark: true});
+    }
+    else { //also wenn auf normal gewechselt werden soll
+        document.getElementById("darkmode").remove(); //entferne vorher erstelltes link-Element aus DOM
+        browser.storage.local.set({isDark: false});
+    }
+}
+
+browser.runtime.sendMessage("show the damn icon"); // Sende irgendwas zum Background, um dort die TabID zu haben
+browser.runtime.onMessage.addListener(onToggleMode); //Sobald das Content-Script eine Message erhält, onToggleMode ausführen
+
+// Antworten-Button Fix
+var comments = document.getElementsByClassName("comment-body");
+for (i=0; i < comments.length; i++) {
+    commBodies[i].parentNode.children[2].setAttribute("class","comments-buttons");
+}
diff --git a/firefox/darken_ps.css b/firefox/darken_ps.css
new file mode 100644
index 0000000..682ec53
--- /dev/null
+++ b/firefox/darken_ps.css
@@ -0,0 +1,67 @@
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 17):
+ * <saphareas@gmail.com> wrote this file.  As long as you retain this notice you
+ * can use this stuff for any non-commercial purposes. If we meet some day,
+ * and you think this stuff is worth it, you can buy me a beer in return.
+ *                                                                Fabian Große
+ * ----------------------------------------------------------------------------
+ */
+
+/* Hintergrund und Textfarbe der Hauptseite */
+body {
+    background-color: #111111;
+    color: #fff;
+}
+
+/* Hintergrund und Textfarbe des Video-Containers */
+.main .container {
+    background-color: #242424;
+    color: #fff;
+}
+
+/* Textfarbe für alle Überschriften */
+h1,
+h2,
+h3,
+h4,
+h5 {
+    color: #fff;
+}
+
+/* Textfarbe für alle Überschriften-Links... */
+h1 a:link,
+h2 a:link,
+h3 a:link,
+h4 a:link,
+h5 a:link {
+    color: #fff;
+}
+
+/* ...auch die bereits besuchten */
+h1 a:visited,
+h2 a:visited,
+h3 a:visited,
+h4 a:visited,
+h5 a:visited {
+    color: #fff;
+}
+
+/* Explizit Textfarbe für... */
+.latestnews-headline, /* Newsüberschriften */
+.ob-rec-text, /* Anzeigenüberschriften */
+.breadcrumb li.active, /* aktives Breadcrumb */
+.comment-body /* Kommentare */ {
+    color: #fff !important;
+}
+
+/* Breadcrumbs etwas dunkler/grauer */
+.breadcrumb a {
+     color: #999;
+}
+
+/* Break-Farbe von Beige auf Weiß zu Schwarz auf Grau */
+hr {
+    border-top: 1px solid #111111;
+    border-bottom: 1px solid #242424;
+}
diff --git a/firefox/icons/action-19.png b/firefox/icons/action-19.png
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index 0000000..135075a
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diff --git a/firefox/icons/action-38.png b/firefox/icons/action-38.png
new file mode 100644
index 0000000..2140b1f
Binary files /dev/null and b/firefox/icons/action-38.png differ
diff --git a/firefox/icons/action-off-19.png b/firefox/icons/action-off-19.png
new file mode 100644
index 0000000..7cf5bd8
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diff --git a/firefox/icons/action-off-38.png b/firefox/icons/action-off-38.png
new file mode 100644
index 0000000..ad1864b
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diff --git a/firefox/icons/icon-128.png b/firefox/icons/icon-128.png
new file mode 100644
index 0000000..c9f7612
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diff --git a/firefox/icons/icon-48.png b/firefox/icons/icon-48.png
new file mode 100644
index 0000000..2eaf5e5
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diff --git a/firefox/icons/icon-96.png b/firefox/icons/icon-96.png
new file mode 100644
index 0000000..bbf39be
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diff --git a/firefox/manifest.json b/firefox/manifest.json
new file mode 100644
index 0000000..d1746fe
--- /dev/null
+++ b/firefox/manifest.json
@@ -0,0 +1,52 @@
+{
+  "manifest_version": 2,
+  "name": "Pietsmiet.de Dark Mode",
+  "shortname": "Dark Pietsmiet",
+  "version": "17.1",
+  "author": "Fabian Große/Saphareas",
+  "homepage_url": "https://github.com/Saphareas/pietsmiet.de-Dark-Mode",
+
+  "description": "Fügt der Pietsmiet.de-Seite ein dunkles Theme/einen Nachtmodus hinzu.",
+
+  "icons": {
+    "48": "icons/icon-48.png",
+    "96": "icons/icon-96.png"
+  },
+
+  "applications": {
+    "gecko": {
+      "id": "{af4fc8a6-ed40-488f-bd74-417b3906f78f}",
+      "strict_min_version": "52.0"
+    }
+  },
+
+  "content_scripts": [
+    {
+      "matches": ["*://*.pietsmiet.de/*"],
+      "js": ["content.js"]
+    }
+  ],
+
+  "background": {
+      "scripts": ["background.js"]
+    },
+
+  "page_action": {
+    "browser_style": true,
+    "default_icon": {
+        "19": "icons/action-off-19.png",
+        "38": "icons/action-off-38.png"
+    },
+    "default_title": "Abdunkeln"
+  },
+
+  "permissions": [
+    "activeTab",
+    "storage"
+  ],
+
+  "web_accessible_resources": [
+      "darken_ps.css"
+  ]
+
+}