diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4d52d45..268af8e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,10 @@
 ## v8.2
 
 * Users are now able to propose corrections to worktimes when they have been marked as for "in review".
+* Added project management. Take a look into the README.md for more information.
+* Administrators can now change the theme globally within TimeTrack. See more within `README.md`.
+* Added `theme_file` and `force_theme` keys to the `app.json` `[general]` section
+* Users can choose their own theme, if `force_theme` is set to `false`
 
 ## v8.1
 
diff --git a/README.md b/README.md
index 61220cf..4ee7138 100644
--- a/README.md
+++ b/README.md
@@ -55,6 +55,8 @@ In step 2, you need to configure the `app.json.sample` within the `api/v1/inc` f
 - `db_*`: Set the connection details for your mysql instance
 - `app`: If set to true, users will be able to use the TimeTrack mobile application
 - `timezone`: Set the timezone of your application, e.g. `Europe/Berlin` or `America/New_York` (default: `UTC`)
+- `force_theme`: Force a theme for all users, this disables the feature allowing users to set their own theme.
+- `theme_file`: If `force_theme` is true, the specified theme is used (default: `/assets/css/v8.css`)
 
 #### **SMTP section**
 
@@ -186,6 +188,15 @@ Users can access their projects within the `Projects` tab.
 
 You can create items for their projects and map worktimes to it. The feature will be reworked in the future.
 
+## Themes
+
+Users can now select their own theme within the `Settings` page. It loads all available themes that reside within the `/assets/css` folder.
+Administrators can enforce a theme globally by setting `force_theme` to `true`. If so, only the theme specified within `theme_file` is available.
+
+To upload a new theme, simply place it into the `/assets/css` folder.
+
+The theme the user selected is saved as a cookie, meaning it is only selected on the current device. On mobile or on another device, the user has to set the desired theme again.
+
 ## Updates
 
 TimeTrack has to be updated in two ways: database and application.
diff --git a/VERSION b/VERSION
index 8d1eec6..0dc0f32 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-8.1
\ No newline at end of file
+8.2
\ No newline at end of file
diff --git a/api/v1/class/arbeitszeit.inc.php b/api/v1/class/arbeitszeit.inc.php
index d83c29d..8810531 100644
--- a/api/v1/class/arbeitszeit.inc.php
+++ b/api/v1/class/arbeitszeit.inc.php
@@ -25,6 +25,7 @@
     use Arbeitszeit\Events\WorktimeMarkedForReviewEvent;
     use Arbeitszeit\Events\WorktimeUnlockedFromReviewEvent;
     use Arbeitszeit\Events\FixEasymodeWorktimeEvent;
+    use Arbeitszeit\Events\WorktimeCorrectionProposedEvent;
     /**
      * Beinhaltet wesentliche Inhalte, wie Einstellungen, Arbeitszeiten erstellen, etc.
      * 
@@ -409,6 +410,8 @@ public function update_worktime($id, $array)
                     return false;
                 }
 
+                EventDispatcherService::get()->dispatch(new WorktimeCorrectionProposedEvent($_SESSION["username"], (int) $id), WorktimeCorrectionProposedEvent::NAME);
+                Exceptions::error_rep("Worktime entry with ID '{$id}' updated successfully.");
                 return true;
             } catch (\PDOException $e) {
                 Exceptions::error_rep("[WORKTIME] Update failed: " . $e->getMessage());
diff --git a/api/v1/class/benutzer/benutzer.arbeit.inc.php b/api/v1/class/benutzer/benutzer.arbeit.inc.php
index e5c410f..3a7a05b 100644
--- a/api/v1/class/benutzer/benutzer.arbeit.inc.php
+++ b/api/v1/class/benutzer/benutzer.arbeit.inc.php
@@ -360,6 +360,50 @@ public function editUserProperties(mixed $username_or_id, string $name, mixed $v
                 return false;
             }
         }
+
+        public function loadUserTheme(){
+
+            $themes = scandir($_SERVER["DOCUMENT_ROOT"] . "/assets/css");
+            $themes = array_diff($themes, [".", ".."]);
+            $check = in_array($_COOKIE["theme"], $themes);
+            if($this->get_app_ini()["general"]["force_theme"] == "true"){
+                return $this->get_app_ini()["general"]["theme_file"];
+            }
+
+            if(!isset($_COOKIE["theme"]) || !$check){
+                return "/assets/css/v8.css";
+            } else {
+                return "/assets/css/" . $_COOKIE["theme"];
+            }
+        }
+
+        public function computeUserThemes(){
+            $themes = scandir($_SERVER["DOCUMENT_ROOT"] . "/assets/css");
+            $themes = array_diff($themes, [".", ".."]);
+            $currentTheme = basename($this->loadUserTheme());
+            foreach($themes as $theme){
+                if($currentTheme == $theme){
+                    echo "<option name='{$theme}' selected>{$theme}</option>";
+                } else {
+                    echo "<option name='{$theme}'>{$theme}</option>";
+                }
+            }
+
+            return true;
+        }
+
+        public function setUserTheme($theme){
+            setcookie("theme", $theme, time()+60*60*24*30, "/");
+            return true;
+        }
+
+        public function checkThemeForce(){
+            if($this->get_app_ini()["general"]["force_theme"] == "true" || $this->get_app_ini()["general"]["force_theme"] == true){
+                return true;
+            } else {
+                return false;
+            }
+        }
     }
 }
 
diff --git a/api/v1/class/events/loader.events.arbeit.inc.php b/api/v1/class/events/loader.events.arbeit.inc.php
index aa3aa3d..bb4ae9e 100644
--- a/api/v1/class/events/loader.events.arbeit.inc.php
+++ b/api/v1/class/events/loader.events.arbeit.inc.php
@@ -21,6 +21,7 @@
 require_once dirname(__DIR__, 1) . "/events/worktimes/WorktimeMarkedForReviewEvent.php";
 require_once dirname(__DIR__, 1) . "/events/worktimes/WorktimeAddedEvent.php";
 require_once dirname(__DIR__, 1) . "/events/worktimes/WorktimeDeletedEvent.php";
+require_once dirname(__DIR__, 1) . "/events/worktimes/WorktimeCorrectionProposedEvent.php";
 
 require_once dirname(__DIR__, 1) . "/events/notifications/CreatedNotificationEvent.php";
 require_once dirname(__DIR__, 1) . "/events/notifications/DeletedNotificationEvent.php";
diff --git a/api/v1/class/events/worktimes/WorktimeCorrectionProposedEvent.php b/api/v1/class/events/worktimes/WorktimeCorrectionProposedEvent.php
new file mode 100644
index 0000000..100771c
--- /dev/null
+++ b/api/v1/class/events/worktimes/WorktimeCorrectionProposedEvent.php
@@ -0,0 +1,27 @@
+<?php
+namespace Arbeitszeit\Events;
+
+use Symfony\Contracts\EventDispatcher\Event;
+
+class WorktimeCorrectionProposedEvent extends Event
+{
+    public const NAME = 'worktimes.correction_proposed';
+
+    private string $username;
+    private int $id;
+    public function __construct(string $username, int $id){
+        $this->username = $username;
+        $this->id = $id;
+    }
+
+    public function getUsername(): string
+    {
+        return $this->username;
+    }
+
+    public function getId(): int
+    {
+        return $this->id;
+    }
+
+}
diff --git a/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_DE.json b/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_DE.json
index 23e1c99..b1811e4 100644
--- a/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_DE.json
+++ b/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_DE.json
@@ -2,7 +2,7 @@
     "subject1": "Deine Arbeitszeit muss geprüft werden!",
     "suject2": "Die Prüfung deiner Arbeitszeit wurde aufgehoben!",
     "greetings": "Hallo",
-    "message1": "dein Vorgesetzter hat deine Arbeitszeit auf Prüfung gesetzt. Die betroffene Arbeitszeit ist unten aufgelistet",
+    "message1": "dein Vorgesetzter hat deine Arbeitszeit auf Prüfung gesetzt. Die betroffene Arbeitszeit ist unten aufgelistet. Du kannst eine Änderung vorschlagen.",
     "message2": "dein Vorgesetzter hat die Prüfung deiner Arbeitszeit aufgehoben. Die betroffene Arbeitszeit ist unten aufgelistet",
     "id": "ID",
     "username": "Benutzername",
diff --git a/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_EN.json b/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_EN.json
index 5414862..cea7f52 100644
--- a/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_EN.json
+++ b/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_EN.json
@@ -2,7 +2,7 @@
   "subject1": "Your working hours need to be reviewed!",
   "suject2": "Your working hours have been unchecked!",
   "greetings": "Hello",
-  "message1": "Your supervisor has put your working hours under review. The affected working hours are listed below",
+  "message1": "Your supervisor has put your working hours under review. The affected working hours are listed below. You can suggest a change.",
   "message2": "Your supervisor has unchecked your working hours. The affected working hours are listed below",
   "id": "ID",
   "username": "Username",
diff --git a/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_NL.json b/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_NL.json
index ae67ab2..3a65415 100644
--- a/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_NL.json
+++ b/api/v1/class/i18n/suite/emails/worktime/uncompliant/snippets_NL.json
@@ -2,7 +2,7 @@
     "subject1": "Uw werktijden moeten worden gecontroleerd!",
     "suject2": "De controle op uw werktijden is geannuleerd!",
     "greetings": "Hallo",
-    "message1": "uw manager heeft uw werktijden beoordeeld. De betreffende werktijden staan ​​hieronder vermeld",
+    "message1": "uw manager heeft uw werktijden beoordeeld. De betreffende werktijden staan ​​hieronder vermeld. U kunt een wijziging voorstellen.",
     "message2": "Uw manager heeft de beoordeling van uw werktijden geannuleerd. De betreffende werktijden worden hieronder vermeld",
     "id": "ID",
     "username": "Gebruikersnaam",
diff --git a/api/v1/inc/app.json.sample b/api/v1/inc/app.json.sample
index 6241a4a..1303b7c 100644
--- a/api/v1/inc/app.json.sample
+++ b/api/v1/inc/app.json.sample
@@ -6,7 +6,9 @@
         "debug": "false",
         "auto_update": "false",
         "app": "false",
-        "timezone": "UTC"
+        "timezone": "UTC",
+        "theme_file": "/assets/css/v8.css",
+        "force_theme": "false"
     },
     "mysql": {
         "db_host": "localhost",
diff --git a/assets/css/cyberpunk.css b/assets/css/cyberpunk.css
new file mode 100644
index 0000000..4e6745d
--- /dev/null
+++ b/assets/css/cyberpunk.css
@@ -0,0 +1,207 @@
+:root {
+  --primary: #ff2e92;
+  --secondary: #00fff7;
+  --bg: #0a0a0f;
+  --text: #f2f2f2;
+  --card: #141421;
+  --radius: 14px;
+  --font-main: "Orbitron", sans-serif;
+  --font-mono: "JetBrains Mono", monospace;
+}
+
+html, body {
+  margin: 0;
+  padding: 0;
+  font-family: var(--font-main);
+  background: radial-gradient(circle at top left, #0f0f1a, #0a0a0f 80%);
+  color: var(--text);
+  min-height: 100vh;
+  overflow-x: hidden;
+  animation: fadeBg 10s ease-in-out infinite alternate;
+}
+
+@keyframes fadeBg {
+  0% { background: radial-gradient(circle at top left, #0f0f1a, #0a0a0f 80%); }
+  100% { background: radial-gradient(circle at top right, #1a0f1f, #0a0a0f 80%); }
+}
+
+a {
+  color: var(--secondary);
+  text-decoration: none;
+  transition: all 0.3s ease;
+}
+a:hover {
+  color: var(--primary);
+  text-shadow: 0 0 8px var(--primary);
+}
+
+h1, h2, h3 {
+  font-weight: 700;
+  letter-spacing: 1px;
+  text-transform: uppercase;
+  color: var(--secondary);
+  text-shadow: 0 0 12px rgba(0,255,247,0.6);
+  animation: fadeSlideUp 0.6s ease-out both;
+}
+
+input, button, textarea {
+  border-radius: var(--radius);
+  border: none;
+  padding: 0.8rem 1rem;
+  margin-top: 0.5rem;
+  font-family: var(--font-main);
+  background: #1a1a2a;
+  color: var(--text);
+  transition: all 0.3s ease;
+}
+input:focus, textarea:focus {
+  outline: none;
+  box-shadow: 0 0 12px var(--secondary);
+}
+
+button {
+  background: var(--primary);
+  color: black;
+  font-weight: bold;
+  cursor: pointer;
+  letter-spacing: 1px;
+  transition: all 0.3s ease, transform 0.2s ease;
+  text-shadow: 0 0 4px rgba(255,255,255,0.2);
+}
+button:hover {
+  background: var(--secondary);
+  color: #0a0a0f;
+  transform: translateY(-2px) scale(1.03);
+  box-shadow: 0 0 15px var(--secondary);
+}
+
+.card {
+  background: var(--card);
+  padding: 2rem;
+  border-radius: var(--radius);
+  border: 1px solid rgba(255,255,255,0.08);
+  box-shadow: 0 0 20px rgba(0,0,0,0.6), 0 0 12px rgba(255,46,146,0.25);
+  transition: transform 0.3s ease, box-shadow 0.3s ease;
+}
+.card:hover {
+  transform: translateY(-3px);
+  box-shadow: 0 0 25px rgba(0,255,247,0.3);
+}
+.card h2 {
+  color: var(--primary);
+}
+
+footer {
+  font-size: 0.85rem;
+  text-align: center;
+  padding: 2rem;
+  color: #aaa;
+  border-top: 1px solid rgba(255,255,255,0.1);
+  background: rgba(20,20,30,0.7);
+  backdrop-filter: blur(8px);
+  animation: glowPulse 4s infinite;
+}
+
+.topnav {
+  display: flex;
+  justify-content: space-between;
+  flex-wrap: wrap;
+  background: rgba(20,20,40,0.8);
+  padding: 0.75rem 1.5rem;
+  border-bottom: 2px solid var(--primary);
+  font-size: 0.95rem;
+  backdrop-filter: blur(6px);
+  animation: slideGlow 6s linear infinite;
+}
+.topnav a {
+  color: var(--text);
+  margin-right: 1rem;
+  padding: 0.3rem 0.5rem;
+}
+.topnav a:hover {
+  color: var(--primary);
+  text-shadow: 0 0 8px var(--primary);
+}
+
+.user-label {
+  font-weight: bold;
+  font-family: var(--font-mono);
+  color: var(--secondary);
+  text-shadow: 0 0 8px var(--secondary);
+}
+
+.nav-version {
+  font-size: 0.8rem;
+  color: var(--primary);
+  font-family: var(--font-mono);
+  margin-left: 1rem;
+}
+
+/* Status Messages */
+.status-message {
+  border-left: 4px solid var(--primary);
+  padding: 1rem 1.5rem;
+  margin-bottom: 1.5rem;
+  border-radius: var(--radius);
+  font-family: var(--font-mono);
+  position: relative;
+  background: rgba(255,255,255,0.05);
+  color: var(--text);
+  animation: fadeSlideUp 0.4s ease;
+}
+.status-message.error { border-left-color: #ff5555; color: #ff9999; }
+.status-message.warn { border-left-color: #ffdd57; color: #ffeaa7; }
+.status-message.info { border-left-color: var(--secondary); }
+
+/* Tables */
+.v8-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 0.95rem;
+  font-family: var(--font-mono);
+  background-color: #151522;
+  border: 1px solid rgba(255,255,255,0.1);
+}
+.v8-table th,
+.v8-table td {
+  padding: 0.75rem 1rem;
+  border-bottom: 1px solid #222;
+}
+.v8-table thead {
+  background-color: #1f1f2f;
+  color: var(--primary);
+  border-bottom: 2px solid var(--primary);
+}
+.v8-table tr:hover {
+  background: rgba(255,46,146,0.07);
+}
+
+/* Log Output */
+.log-output {
+  font-family: var(--font-mono);
+  font-size: 0.85rem;
+  background: #111;
+  padding: 1rem;
+  border-radius: var(--radius);
+  border: 1px solid rgba(255,255,255,0.08);
+  color: var(--secondary);
+  max-height: 300px;
+  overflow-y: auto;
+}
+.log-output .error { color: #ff2e92; font-weight: bold; }
+.log-output .warn { color: #ffdd57; }
+.log-output .info { color: var(--secondary); }
+
+/* Animations */
+@keyframes fadeSlideUp {
+  from { opacity: 0; transform: translateY(12px); }
+  to { opacity: 1; transform: translateY(0); }
+}
+@keyframes glowPulse {
+  0%,100% { box-shadow: 0 0 0px rgba(255,46,146,0); }
+  50% { box-shadow: 0 0 12px rgba(255,46,146,0.4); }
+}
+@keyframes slideGlow {
+  0% { border-image: linear-gradient(90deg, var(--primary), var(--secondary)) 1; }
+  100% { border-image: linear-gradient(90deg, var(--secondary), var(--primary)) 1; }
+}
diff --git a/assets/css/glassy.css b/assets/css/glassy.css
new file mode 100644
index 0000000..8bcddd2
--- /dev/null
+++ b/assets/css/glassy.css
@@ -0,0 +1,167 @@
+:root {
+  --primary: #4ae;
+  --bg: #0d1117;
+  --text: #e6edf3;
+  --card: rgba(255, 255, 255, 0.05);
+  --radius: 14px;
+  --font-main: "Inter", sans-serif;
+  --font-mono: "JetBrains Mono", monospace;
+  --glass-blur: 12px;
+}
+
+/* === Base Layout === */
+html, body {
+  margin: 0;
+  padding: 0;
+  font-family: var(--font-main);
+  background: linear-gradient(135deg, #0d1117 0%, #161b22 100%);
+  color: var(--text);
+  min-height: 100vh;
+  overflow-x: hidden;
+}
+
+/* === Links === */
+a {
+  color: var(--primary);
+  text-decoration: none;
+  font-weight: 500;
+  transition: color 0.2s ease;
+}
+a:hover {
+  color: #7bcfff;
+  text-decoration: underline;
+}
+
+/* === Headings === */
+h1, h2, h3 {
+  font-weight: 700;
+  letter-spacing: -0.5px;
+}
+
+/* === Inputs & Buttons === */
+input, button, textarea, select {
+  border-radius: var(--radius);
+  border: none;
+  padding: 0.75rem 1rem;
+  margin-top: 0.5rem;
+  font-family: var(--font-main);
+  backdrop-filter: blur(var(--glass-blur));
+  background: rgba(255, 255, 255, 0.05);
+  color: var(--text);
+  transition: all 0.3s ease;
+}
+
+input:focus, textarea:focus, select:focus {
+  outline: none;
+  border: 1px solid var(--primary);
+  box-shadow: 0 0 10px rgba(74, 174, 255, 0.4);
+}
+
+button {
+  background: var(--primary);
+  color: #0d1117;
+  cursor: pointer;
+  font-weight: 600;
+}
+button:hover {
+  background: #3cb0ff;
+  transform: translateY(-2px);
+  box-shadow: 0 6px 20px rgba(74,174,255,0.3);
+}
+
+/* === Cards === */
+.card {
+  background: var(--card);
+  backdrop-filter: blur(var(--glass-blur));
+  padding: 2rem;
+  border-radius: var(--radius);
+  box-shadow: 0 6px 25px rgba(0,0,0,0.35);
+  border: 1px solid rgba(255,255,255,0.1);
+  transition: transform 0.2s ease;
+}
+.card:hover {
+  transform: translateY(-3px);
+}
+
+/* === Top Navigation === */
+.topnav {
+  display: flex;
+  justify-content: space-between;
+  flex-wrap: wrap;
+  background: rgba(255, 255, 255, 0.04);
+  backdrop-filter: blur(var(--glass-blur));
+  padding: 0.75rem 1.5rem;
+  border-bottom: 1px solid rgba(255,255,255,0.08);
+}
+
+.topnav a {
+  color: var(--text);
+  margin-right: 1rem;
+  padding: 0.4rem 0.6rem;
+  border-radius: 6px;
+  transition: background 0.2s ease;
+}
+.topnav a:hover {
+  background: rgba(255,255,255,0.08);
+}
+
+.user-label {
+  font-weight: bold;
+  font-family: var(--font-mono);
+  color: var(--primary);
+}
+
+/* === Tables === */
+.v8-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 0.95rem;
+  font-family: var(--font-mono);
+  backdrop-filter: blur(var(--glass-blur));
+  background-color: rgba(255,255,255,0.05);
+  border: 1px solid rgba(255,255,255,0.1);
+  border-radius: var(--radius);
+  overflow: hidden;
+}
+
+.v8-table th {
+  background: rgba(255,255,255,0.08);
+  color: var(--primary);
+  padding: 1rem;
+  text-align: left;
+}
+.v8-table td {
+  padding: 0.9rem 1rem;
+  border-bottom: 1px solid rgba(255,255,255,0.07);
+}
+.v8-table tr:hover {
+  background: rgba(74,174,255,0.05);
+}
+
+/* === Status Messages === */
+.status-message {
+  border-left: 4px solid var(--primary);
+  padding: 1rem 1.5rem;
+  margin-bottom: 1.5rem;
+  border-radius: var(--radius);
+  background: rgba(255, 255, 255, 0.04);
+  backdrop-filter: blur(var(--glass-blur));
+}
+
+.status-message.error { border-left-color: #e74c3c; }
+.status-message.warn { border-left-color: #f1c40f; }
+.status-message.info { border-left-color: #3498db; }
+
+/* === Footer === */
+footer {
+  text-align: center;
+  padding: 2rem;
+  font-size: 0.85rem;
+  color: #aaa;
+  backdrop-filter: blur(var(--glass-blur));
+  background: rgba(255,255,255,0.03);
+  border-top: 1px solid rgba(255,255,255,0.07);
+}
+footer:hover {
+  background: rgba(255,255,255,0.06);
+}
diff --git a/assets/css/nord.css b/assets/css/nord.css
new file mode 100644
index 0000000..8940f82
--- /dev/null
+++ b/assets/css/nord.css
@@ -0,0 +1,209 @@
+:root {
+  --primary: #88c0d0;
+  --bg: #2e3440;
+  --text: #d8dee9;
+  --card: #3b4252;
+  --radius: 12px;
+  --font-main: "Fira Sans", sans-serif;
+  --font-mono: "JetBrains Mono", monospace;
+}
+
+html, body {
+  margin: 0;
+  padding: 0;
+  font-family: var(--font-main);
+  background: var(--bg);
+  color: var(--text);
+  min-height: 100vh;
+  overflow-x: hidden;
+}
+
+a {
+  color: var(--primary);
+  text-decoration: none;
+}
+a:hover {
+  text-decoration: underline;
+}
+
+h1, h2, h3 {
+  font-weight: 600;
+  color: #eceff4;
+}
+
+input, button, textarea {
+  border-radius: var(--radius);
+  border: none;
+  padding: 0.75rem;
+  margin-top: 0.5rem;
+  font-family: var(--font-main);
+  background: #434c5e;
+  color: var(--text);
+}
+
+button {
+  background: var(--primary);
+  color: #2e3440;
+  cursor: pointer;
+  font-weight: bold;
+  transition: background 0.3s;
+}
+button:hover {
+  background: #81a1c1;
+}
+
+.card {
+  background-color: var(--card);
+  padding: 2rem;
+  border-radius: var(--radius);
+  box-shadow: 0 0 12px rgba(0,0,0,0.4);
+}
+.card h1, .card h2, .card h3 {
+  color: var(--primary);
+}
+.card p, .card ul, .card code {
+  line-height: 1.6;
+  font-size: 0.95rem;
+}
+
+footer {
+  font-size: 0.85rem;
+  text-align: center;
+  padding: 2rem;
+  color: #88c0d0;
+  border-top: 1px solid #4c566a;
+  margin-top: 2rem;
+}
+
+/* === Navigation === */
+.topnav {
+  display: flex;
+  justify-content: space-between;
+  flex-wrap: wrap;
+  background: #3b4252;
+  padding: 0.75rem 1.5rem;
+  box-shadow: 0 2px 4px rgba(0,0,0,0.5);
+  font-size: 0.95rem;
+  border-bottom: 1px solid #4c566a;
+}
+.topnav a {
+  color: var(--text);
+  margin-right: 1rem;
+  padding: 0.3rem 0.5rem;
+  transition: color 0.2s;
+}
+.topnav a:hover {
+  color: var(--primary);
+}
+.topnav .topnav-right {
+  display: flex;
+  align-items: center;
+  gap: 1rem;
+}
+.user-label {
+  font-weight: bold;
+  font-family: var(--font-mono);
+  color: var(--primary);
+}
+.nav-version {
+  font-size: 0.8rem;
+  color: #bf616a;
+  font-family: var(--font-mono);
+  margin-left: 1rem;
+}
+
+/* === Status Messages === */
+.status-message {
+  background-color: rgba(136, 192, 208, 0.12);
+  border-left: 4px solid var(--primary);
+  padding: 1rem 1.5rem;
+  margin-bottom: 1.5rem;
+  border-radius: var(--radius);
+  font-family: var(--font-mono);
+  position: relative;
+  animation: fadeIn 0.4s ease;
+  color: var(--text);
+}
+.status-message.error {
+  background-color: rgba(191, 97, 106, 0.12);
+  border-left-color: #bf616a;
+}
+.status-message.warn {
+  background-color: rgba(235, 203, 139, 0.12);
+  border-left-color: #ebcb8b;
+}
+.status-message.info {
+  background-color: rgba(129, 161, 193, 0.12);
+  border-left-color: #81a1c1;
+}
+.status-message .dismiss-button {
+  position: absolute;
+  top: 0.7rem;
+  right: 1rem;
+  background: none;
+  border: none;
+  color: #aaa;
+  font-size: 1.2rem;
+  cursor: pointer;
+  transition: color 0.2s ease;
+}
+.status-message .dismiss-button:hover {
+  color: var(--primary);
+}
+
+/* === Tables === */
+.v8-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 0.95rem;
+  font-family: var(--font-mono);
+  background-color: var(--card);
+  border: 1px solid #4c566a;
+}
+.v8-table th,
+.v8-table td {
+  padding: 0.75rem 1rem;
+  text-align: left;
+  border-bottom: 1px solid #434c5e;
+}
+.v8-table thead {
+  background-color: #434c5e;
+  color: var(--primary);
+  border-bottom: 2px solid var(--primary);
+}
+.v8-table tr:hover {
+  background-color: rgba(136, 192, 208, 0.08);
+  transition: background 0.2s;
+}
+
+/* === Log Output === */
+.log-output {
+  font-family: var(--font-mono);
+  font-size: 0.85rem;
+  background-color: #3b4252;
+  padding: 1rem;
+  border-radius: var(--radius);
+  margin-top: 1rem;
+  white-space: pre-wrap;
+  word-break: break-word;
+  border: 1px solid #4c566a;
+  color: #eceff4;
+  max-height: 300px;
+  overflow-y: auto;
+}
+.log-output .error {
+  color: #bf616a;
+  font-weight: bold;
+}
+.log-output .warn {
+  color: #ebcb8b;
+}
+.log-output .info {
+  color: #81a1c1;
+}
+
+/* === Animations === */
+@keyframes fadeIn {
+  from { opacity: 0; transform: translateY(-5px); }
+  to { opacity: 1; transform: translateY(0); }
+}
diff --git a/composer.json b/composer.json
index 857d0ea..15b8cb9 100644
--- a/composer.json
+++ b/composer.json
@@ -3,7 +3,7 @@
   "description": "TimeTrack is a PHP-written time recording tool for small businesses",
   "type": "software",
   "license": "GNU GPL",
-  "version": "8.1",
+  "version": "8.2",
   "authors": [
     {
       "name": "Bryan Boehnke-Avan",
diff --git a/errors/500.php b/errors/500.php
index 6f928bd..c76512d 100644
--- a/errors/500.php
+++ b/errors/500.php
@@ -15,7 +15,7 @@
   <title>500 | Internal Server Error</title>
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-  <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+  <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 <body>
   <div class="animated-bg"></div>
diff --git a/suite/actions/users/change_theme.php b/suite/actions/users/change_theme.php
new file mode 100644
index 0000000..e97203a
--- /dev/null
+++ b/suite/actions/users/change_theme.php
@@ -0,0 +1,10 @@
+<?php
+require $_SERVER["DOCUMENT_ROOT"] . "/api/v1/inc/arbeit.inc.php";
+use Arbeitszeit\Arbeitszeit;
+$arbeit = new Arbeitszeit;
+$base_url = $arbeit->get_app_ini()["general"]["base_url"];
+$arbeit->auth()->login_validation();
+
+if($arbeit->benutzer()->setUserTheme($_POST["theme"])){
+    header("Location: /suite/users/settings.php");
+}
\ No newline at end of file
diff --git a/suite/admin/notifications/edit.php b/suite/admin/notifications/edit.php
index 45ac113..afe7016 100644
--- a/suite/admin/notifications/edit.php
+++ b/suite/admin/notifications/edit.php
@@ -23,7 +23,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/admin/projects/addUser.php b/suite/admin/projects/addUser.php
index baf8af8..f29795d 100644
--- a/suite/admin/projects/addUser.php
+++ b/suite/admin/projects/addUser.php
@@ -20,7 +20,7 @@
 <head>
     <meta charset="UTF-8">
     <title><?= $language["title"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 <body>
 <?php include $_SERVER["DOCUMENT_ROOT"] . "/assets/gui/standard_nav.php"; ?>
@@ -31,7 +31,7 @@
         <input type="hidden" name="project" value="<?= htmlspecialchars($projectId); ?>">
 
         <label><?= $language["label_userid"]; ?>:</label><br>
-        <input type="text" name="projectId" value="<?= $_GET["project"]; ?>" hidden>
+        <input type="text" name="projectId" value="<?= $arbeit->i18n()->sanitizeOutput($_GET["project"]); ?>" hidden>
         <input type="text" name="userId" required>
         <br><br>
         <label><?= $language["label_role"]; ?>:</label><br>
@@ -42,7 +42,7 @@
         <span class="tooltip-text"><?= $language["tooltip_permissions"]; ?></span>
         <br><br>
         <button type="submit" class="v8-button"><?= $language["btn_add"]; ?></button><br>
-        <a href="/suite/projects/view.php?id=<?= $projectId; ?>" class="v8-button secondary"><?= $language["btn_cancel"]; ?></a>
+        <a href="/suite/projects/view.php?id=<?= $arbeit->i18n()->sanitizeOutput($projectId); ?>" class="v8-button secondary"><?= $language["btn_cancel"]; ?></a>
     </form>
 </main>
 </body>
diff --git a/suite/admin/projects/admin.php b/suite/admin/projects/admin.php
index 1c89cef..fbda32c 100644
--- a/suite/admin/projects/admin.php
+++ b/suite/admin/projects/admin.php
@@ -27,7 +27,7 @@
 <head>
     <meta charset="UTF-8">
     <title><?= $language["title"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/admin/projects/edit.php b/suite/admin/projects/edit.php
index 9d0e721..dd776bc 100644
--- a/suite/admin/projects/edit.php
+++ b/suite/admin/projects/edit.php
@@ -28,7 +28,7 @@
 <head>
     <meta charset="UTF-8">
     <title><?= $language["title"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 <body>
     <?php include $_SERVER["DOCUMENT_ROOT"] . "/assets/gui/standard_nav.php"; ?>
@@ -39,7 +39,7 @@
         <div class="card v8-bordered">
             <form action="/suite/admin/actions/projects/edit.php" method="POST">
                 <!-- Hidden ID -->
-                <input type="hidden" name="id" value="<?= $project["id"] ?? $projectId; ?>">
+                <input type="hidden" name="id" value="<?= $arbeit->i18n()->sanitizeOutput($project["id"] ?? $projectId); ?>">
 
                 <label><?= $language["label_name"]; ?>:</label><br>
                 <input type="text" name="name" value="<?= htmlspecialchars($project["name"] ?? ""); ?>" required>
@@ -48,10 +48,10 @@
                 <textarea name="description"><?= htmlspecialchars($project["description"] ?? ""); ?></textarea>
                 <br><br>
                 <label><?= $language["label_deadline"]; ?>:</label><br>
-                <input type="date" name="deadline" value="<?= $project["deadline"] ?? ""; ?>">
+                <input type="date" name="deadline" value="<?= $arbeit->i18n()->sanitizeOutput($project["deadline"] ?? ""); ?>">
                 <br><br>
                 <label><?= $language["label_owner"]; ?>:</label><br>
-                <input type="text" name="owner" value="<?= $project["owner"] ?? ""; ?>" placeholder="UserID">
+                <input type="text" name="owner" value="<?= $arbeit->i18n()->sanitizeOutput($project["owner"] ?? ""); ?>" placeholder="UserID">
                 <br>
                 <button type="submit" name="submit" class="v8-button"><?= $language["btn_save"]; ?></button><br><br>
                 <a href="admin.php" class="v8-button secondary"><?= $language["btn_cancel"]; ?></a>
diff --git a/suite/admin/users/edit.php b/suite/admin/users/edit.php
index a140057..b41d168 100644
--- a/suite/admin/users/edit.php
+++ b/suite/admin/users/edit.php
@@ -24,7 +24,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/admin/worktime/all.php b/suite/admin/worktime/all.php
index 3e2c103..96ab5c3 100644
--- a/suite/admin/worktime/all.php
+++ b/suite/admin/worktime/all.php
@@ -26,7 +26,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/admin/worktime/sick/all.php b/suite/admin/worktime/sick/all.php
index bc47ac9..fbd7877 100644
--- a/suite/admin/worktime/sick/all.php
+++ b/suite/admin/worktime/sick/all.php
@@ -28,7 +28,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/admin/worktime/vacation/all.php b/suite/admin/worktime/vacation/all.php
index b980c7a..fb32322 100644
--- a/suite/admin/worktime/vacation/all.php
+++ b/suite/admin/worktime/vacation/all.php
@@ -26,7 +26,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/forgot_password.php b/suite/forgot_password.php
index 212a659..6a3c1ff 100644
--- a/suite/forgot_password.php
+++ b/suite/forgot_password.php
@@ -15,7 +15,7 @@
     
     <!-- Fonts & Style -->
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/index.php b/suite/index.php
index cd3f178..4001fc8 100644
--- a/suite/index.php
+++ b/suite/index.php
@@ -18,7 +18,7 @@
 
     <!-- Fonts & CSS -->
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 
     <!-- JS Libraries -->
     <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.min.js" defer></script>
diff --git a/suite/login.php b/suite/login.php
index b30eb3c..2aa78aa 100644
--- a/suite/login.php
+++ b/suite/login.php
@@ -19,7 +19,7 @@
   <title><?= $language["title"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-  <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+  <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 <body>
   <div class="animated-bg"></div>
diff --git a/suite/notifications/all.php b/suite/notifications/all.php
index 3e45379..cc19b3b 100644
--- a/suite/notifications/all.php
+++ b/suite/notifications/all.php
@@ -19,7 +19,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/notifications/view.php b/suite/notifications/view.php
index d443620..aa7f0ab 100644
--- a/suite/notifications/view.php
+++ b/suite/notifications/view.php
@@ -23,7 +23,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 
     <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.min.js" defer></script>
     <script src="https://code.jquery.com/jquery-3.4.1.min.js" defer></script>
diff --git a/suite/plugins/index.php b/suite/plugins/index.php
index 22945eb..f134e6b 100644
--- a/suite/plugins/index.php
+++ b/suite/plugins/index.php
@@ -17,7 +17,7 @@
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap"
         rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/privacy.php b/suite/privacy.php
index 43c58f7..794c7bf 100644
--- a/suite/privacy.php
+++ b/suite/privacy.php
@@ -14,7 +14,7 @@
   <title><?= $loc["h1"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-  <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+  <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme() ?>?v=1">
 </head>
 <body>
   <div class="animated-bg"></div>
diff --git a/suite/projects/createItem.php b/suite/projects/createItem.php
index 554ab39..687454a 100644
--- a/suite/projects/createItem.php
+++ b/suite/projects/createItem.php
@@ -17,7 +17,7 @@
 <head>
     <meta charset="UTF-8">
     <title><?= $language["title"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 <body>
 <?php include $_SERVER["DOCUMENT_ROOT"] . "/assets/gui/standard_nav.php"; ?>
@@ -37,7 +37,7 @@
         <input type="text" name="assignee">
         <br><br>
         <button type="submit" class="v8-button"><?= $language["btn_save"]; ?></button><br>
-        <a href="view.php?id=<?= $projectId; ?>" class="v8-button secondary"><?= $language["btn_cancel"]; ?></a>
+        <a href="view.php?id=<?= $arbeit->i18n()->sanitizeOutput($projectId); ?>" class="v8-button secondary"><?= $language["btn_cancel"]; ?></a>
     </form>
 </main>
 </body>
diff --git a/suite/projects/item.php b/suite/projects/item.php
index 0c72132..1daf28d 100644
--- a/suite/projects/item.php
+++ b/suite/projects/item.php
@@ -21,7 +21,7 @@
 
 $item = $arbeit->projects()->getItem($itemId);
 $project = $arbeit->projects()->getProject($item["id"]);
-$worktimes = $arbeit->projects()->getUserProjectWorktimes($project["id"], $user);
+$worktimes = $arbeit->projects()->getUserProjectWorktimes($project["id"]);
 
 ?>
 <!DOCTYPE html>
@@ -29,7 +29,7 @@
 <head>
     <meta charset="UTF-8">
     <title><?= $language["title"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 <body>
     <?php include $_SERVER["DOCUMENT_ROOT"] . "/assets/gui/standard_nav.php"; ?>
@@ -38,10 +38,10 @@
         <h1><?= htmlspecialchars($item["title"] ?? $language["title"]); ?></h1>
         <p><?= htmlspecialchars($item["description"] ?? $language["no_description"]); ?></p>
 
-        <p><strong><?= $language["project"]; ?>:</strong> <?= $project["name"] ?? "-"; ?></p>
+        <p><strong><?= $language["project"]; ?>:</strong> <?= $arbeit->i18n()->sanitizeOutput($project["name"] ?? "-"); ?></p>
         <p><strong><?= $language["assignee"]; ?>:</strong> <?= $arbeit->benutzer()->get_user_from_id($item["assignee"])["name"] ?? "-"; ?></p>
-        <p><strong><?= $language["status"]; ?>:</strong> <?= $item["status"] ?? "Open"; ?></p>
-        <p><strong><?= $language["id"]; ?></strong>: <?= $item["itemid"]; ?></p>
+        <p><strong><?= $language["status"]; ?>:</strong> <?= $arbeit->i18n()->sanitizeOutput($item["status"] ?? "Open"); ?></p>
+        <p><strong><?= $language["id"]; ?></strong>: <?= $arbeit->i18n()->sanitizeOutput($item["itemid"] ?? ""); ?></p>
 
         <div class="card v8-bordered" style="margin-top:2rem;">
             <h2><?= $language["worktimes"]; ?></h2>
@@ -56,9 +56,9 @@
                 <tbody>
                     <?php foreach($worktimes as $w): ?>
                         <tr>
-                            <td><?= $w["user"]; ?></td>
-                            <td><?= $w["hours"] ?? "-"; ?></td>
-                            <td><?= $w["date"] ?? "-"; ?></td>
+                            <td><?= $arbeit->i18n()->sanitizeOutput($w["user"] ?? "-"); ?></td>
+                            <td><?= $arbeit->i18n()->sanitizeOutput($w["hours"] ?? "-"); ?></td>
+                            <td><?= $arbeit->i18n()->sanitizeOutput($w["date"] ?? "-"); ?></td>
                         </tr>
                     <?php endforeach; ?>
                     <?php if(empty($worktimes)): ?>
@@ -69,8 +69,8 @@
         </div>
 
         <div class="card v8-bordered" style="margin-top:2rem; text-align:center;">
-            <a href="edit_item.php?id=<?= $itemId; ?>" class="v8-button"><?= $language["btn_edit"]; ?></a>
-            <a href="delete_item.php?id=<?= $itemId; ?>" class="v8-button danger"><?= $language["btn_delete"]; ?></a>
+            <a href="edit_item.php?id=<?= $arbeit->i18n()->sanitizeOutput($itemId); ?>" class="v8-button"><?= $language["btn_edit"]; ?></a>
+            <a href="delete_item.php?id=<?= $arbeit->i18n()->sanitizeOutput($itemId); ?>" class="v8-button danger"><?= $language["btn_delete"]; ?></a>
         </div>
     </main>
 </body>
diff --git a/suite/projects/mapWorktimeToItem.php b/suite/projects/mapWorktimeToItem.php
index 761d30c..ee4421d 100644
--- a/suite/projects/mapWorktimeToItem.php
+++ b/suite/projects/mapWorktimeToItem.php
@@ -16,7 +16,7 @@
 <head>
     <meta charset="UTF-8">
     <title>Map Worktime | <?= $ini["general"]["app_name"]; ?></title>
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 <body>
 <?php include $_SERVER["DOCUMENT_ROOT"] . "/assets/gui/standard_nav.php"; ?>
@@ -36,7 +36,7 @@
         <input type="text" name="user_id">
         <br><br>
         <button type="submit" class="v8-button">Map</button><br>
-        <a href="view.php?id=<?= $projectId; ?>" class="v8-button secondary">Cancel</a>
+        <a href="view.php?id=<?= $arbeit->i18n()->sanitizeOutput($projectId); ?>" class="v8-button secondary">Cancel</a>
     </form>
 </main>
 </body>
diff --git a/suite/projects/overview.php b/suite/projects/overview.php
index aa0220b..8147062 100644
--- a/suite/projects/overview.php
+++ b/suite/projects/overview.php
@@ -25,7 +25,7 @@
 <head>
     <meta charset="UTF-8">
     <title><?= $language["title"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 <body>
     <?php include $_SERVER["DOCUMENT_ROOT"] . "/assets/gui/standard_nav.php"; ?>
diff --git a/suite/projects/view.php b/suite/projects/view.php
index a4a3ed4..05abe17 100644
--- a/suite/projects/view.php
+++ b/suite/projects/view.php
@@ -30,7 +30,7 @@
 <head>
     <meta charset="UTF-8">
     <title><?= $language["title"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
     <style>
         .section-header {
             display: flex;
@@ -45,7 +45,7 @@
     <main style="max-width: 1080px; margin: 0 auto; padding: 2rem;">
         <h1><?= htmlspecialchars($project["name"] ?? $language["title"]); ?></h1>
         <p><?= $language["description"] ?>: <?= htmlspecialchars($project["description"] ?? $language["no_description"]); ?></p>
-        <p><strong><?= $language["deadline"]; ?>:</strong> <?= $project["deadline"] ?? "-"; ?></p>
+        <p><strong><?= $language["deadline"]; ?>:</strong> <?= $arbeit->i18n()->sanitizeOutput($project["deadline"] ?? "-"); ?></p>
 
         <!-- Tabs -->
         <div class="tabs">
@@ -74,9 +74,9 @@
                         <tr>
                             <td><?= htmlspecialchars($i["title"]); ?></td>
                             <td><?= $arbeit->benutzer()->get_user_from_id($i["assignee"])["name"] ?? "-"; ?></td>
-                            <td><?= $i["status"] ?? "Open"; ?></td>
-                            <td><a href="item.php?id=<?= $i["id"]; ?>" class="v8-button"><?= $language["btn_view"]; ?></a></td>
-                            <td><?= $i["itemid"]; ?></td>
+                            <td><?= $arbeit->i18n()->sanitizeOutput($i["status"] ?? "Open"); ?></td>
+                            <td><a href="item.php?id=<?= $arbeit->i18n()->sanitizeOutput($i["id"]); ?>" class="v8-button"><?= $language["btn_view"]; ?></a></td>
+                            <td><?= $arbeit->i18n()->sanitizeOutput($i["itemid"] ?? ""); ?></td>
                         </tr>
                     <?php endforeach; ?>
                     <?php if(empty($items)): ?>
@@ -91,12 +91,12 @@
                 <h2><?= $language["members"]; ?></h2>
                 <?php $isAdmin = $arbeit->benutzer()->get_current_user()["isAdmin"]; ?>
                 <?php if($isAdmin): ?>
-                    <a href="/suite/admin/projects/addUser.php?project=<?= $projectId; ?>" class="v8-button">+</a>
+                    <a href="/suite/admin/projects/addUser.php?project=<?= $arbeit->i18n()->sanitizeOutput($projectId); ?>" class="v8-button">+</a>
                 <?php endif; ?>
             </div>
             <ul>
                 <?php foreach($members as $m): ?>
-                    <li><?= $m["name"]; ?> (<?= $m["role"]; ?>) - UserID: <?= $m["userid"]; ?></li>
+                    <li><?= $arbeit->i18n()->sanitizeOutput($m["name"]); ?> (<?= $arbeit->i18n()->sanitizeOutput($m["role"]); ?>) - UserID: <?= $arbeit->i18n()->sanitizeOutput($m["userid"]); ?></li>
                 <?php endforeach; ?>
                 <?php if(empty($members)): ?>
                     <li><?= $language["no_members"]; ?></li>
@@ -107,7 +107,7 @@
         <div id="worktimes" class="tab-content" style="display:none;">
             <div class="section-header">
                 <h2><?= $language["worktimes"]; ?></h2>
-                <a href="/suite/projects/mapWorktimeToItem.php?project=<?= $projectId; ?>" class="v8-button">+</a>
+                <a href="/suite/projects/mapWorktimeToItem.php?project=<?= $arbeit->i18n()->sanitizeOutput($projectId); ?>" class="v8-button">+</a>
             </div>
             <table class="v8-table">
                 <thead>
@@ -120,9 +120,9 @@
                 <tbody>
                     <?php foreach($worktimes as $w): ?>
                         <tr>
-                            <td><?= $w["user"]; ?></td>
-                            <td><?= $w["itemid"]; ?></td>
-                            <td><?= $w["hours"] ?? "-"; ?></td>
+                            <td><?= $arbeit->benutzer()->get_user_from_id($w["user"])["name"] ?? "-"; ?></td>
+                            <td><?= $arbeit->i18n()->sanitizeOutput($w["itemid"] ?? ""); ?></td>
+                            <td><?= $arbeit->i18n()->sanitizeOutput($w["hours"] ?? "-"); ?></td>
                         </tr>
                     <?php endforeach; ?>
                     <?php if(empty($worktimes)): ?>
diff --git a/suite/users/changes.php b/suite/users/changes.php
index f5733ea..9c9556a 100644
--- a/suite/users/changes.php
+++ b/suite/users/changes.php
@@ -17,7 +17,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 
     <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.min.js" defer></script>
     <script src="https://code.jquery.com/jquery-3.4.1.min.js" defer></script>
diff --git a/suite/users/settings.php b/suite/users/settings.php
index 87ac1b4..792a67e 100644
--- a/suite/users/settings.php
+++ b/suite/users/settings.php
@@ -18,7 +18,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
@@ -56,6 +56,26 @@
             <form action="/suite/actions/users/toggle_easymode.php" method="POST" style="margin-top: 1rem;">
                 <button type="submit"><?= $loc["easymode_toggle"]; ?></button>
             </form>
+
+            <hr>
+            
+            <form action="/suite/actions/users/change_theme.php" method="POST">
+                <h2>Select theme</h2>
+                <label for="theme">Select a theme:</label>
+                <select name="theme" id="theme" onchange="this.form.submit()">
+                    <?php 
+                    if($arbeit->benutzer()->checkThemeForce()){
+                        $noTheme =  "<p>You cannot select a theme, since your administrator doesn't allow this feature!</p>";
+                    } else {
+                        unset($noTheme);
+                        $arbeit->benutzer()->computeUserThemes();
+                    }
+                    
+                    
+                    ?>
+                </select>
+                <?= $noTheme; ?>
+            </form>
         </div>
 
         <h2 style="margin-top: 3rem;"><?= $loc["support"]; ?></h2>
diff --git a/suite/worktime/all.php b/suite/worktime/all.php
index 4857f4e..261d67b 100644
--- a/suite/worktime/all.php
+++ b/suite/worktime/all.php
@@ -23,7 +23,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/worktime/correction.php b/suite/worktime/correction.php
index c946fa8..d074c58 100644
--- a/suite/worktime/correction.php
+++ b/suite/worktime/correction.php
@@ -25,7 +25,7 @@
 <head>
     <meta charset="UTF-8">
     <title><?= $language["title"]; ?> | <?= $ini["general"]["app_name"]; ?></title>
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 <body>
 <?php include $_SERVER["DOCUMENT_ROOT"] . "/assets/gui/standard_nav.php"; ?>
@@ -35,16 +35,16 @@
 
     <div class="card v8-bordered" style="margin-bottom: 2rem;">
         <h2><?= $language["h2"]; ?></h2>
-        <p><strong><?= $language["start"]; ?>:</strong> <?= $worktime["schicht_anfang"] ?? "?" ?></p>
-        <p><strong><?= $language["end"]; ?>:</strong> <?= $worktime["schicht_ende"] ?? "?" ?></p>
-        <p><strong><?= $language["comment"]; ?>:</strong> <?= $worktime["ort"] ?? "-" ?></p>
-        <p><strong><?= $language["date"]; ?>:</strong> <?= $worktime["schicht_tag"] ?? "-" ?></p>
+        <p><strong><?= $language["start"]; ?>:</strong> <?= $arbeit->i18n()->sanitizeOutput($worktime["schicht_anfang"] ?? "?"); ?></p>
+        <p><strong><?= $language["end"]; ?>:</strong> <?= $arbeit->i18n()->sanitizeOutput($worktime["schicht_ende"] ?? "?"); ?></p>
+        <p><strong><?= $language["comment"]; ?>:</strong> <?= $arbeit->i18n()->sanitizeOutput($worktime["ort"] ?? "-"); ?></p>
+        <p><strong><?= $language["date"]; ?>:</strong> <?= $arbeit->i18n()->sanitizeOutput($worktime["schicht_tag"] ?? "-"); ?></p>
     </div>
 
     <div class="card v8-bordered" style="text-align: center;">
         <h2><?= $language["suggest_change"]; ?></h2>
         <form action="/suite/actions/worktime/correction.php" method="POST">
-            <input type="hidden" name="worktime_id" value="<?= $worktimeId ?>">
+            <input type="hidden" name="worktime_id" value="<?= $arbeit->i18n()->sanitizeOutput($worktimeId); ?>">
 
             <label><?= $language["new_start"]; ?>:</label><br>
             <input type="time" data-date-format="DD.MM.YYYY" name="new_start"><br>
diff --git a/suite/worktime/sick/index.php b/suite/worktime/sick/index.php
index e74be6b..330dbde 100644
--- a/suite/worktime/sick/index.php
+++ b/suite/worktime/sick/index.php
@@ -15,7 +15,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>
diff --git a/suite/worktime/vacation/index.php b/suite/worktime/vacation/index.php
index 51ec500..69c88d8 100644
--- a/suite/worktime/vacation/index.php
+++ b/suite/worktime/vacation/index.php
@@ -17,7 +17,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&family=JetBrains+Mono&display=swap" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/v8.css?v=1">
+    <link rel="stylesheet" href="<?= $arbeit->benutzer()->loadUserTheme(); ?>?v=1">
 </head>
 
 <body>