diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index 1c63d54..15503c2 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -1,5 +1,9 @@
 # Copilot instructions for infoscreen_2025
 
+# Purpose
+These instructions tell Copilot Chat how to reason about this codebase.
+Prefer explanations and refactors that align with these structures.
+
 Use this as your shared context when proposing changes. Keep edits minimal and match existing patterns referenced below.
 
 ## Big picture
diff --git a/dashboard/src/appointments.tsx b/dashboard/src/appointments.tsx
index 8f3ac47..6be0b5a 100644
--- a/dashboard/src/appointments.tsx
+++ b/dashboard/src/appointments.tsx
@@ -387,7 +387,7 @@ const Appointments: React.FC = () => {
 
   return (
     <div>
-      <h1 className="text-2xl font-bold mb-4">Terminmanagement</h1>
+      <h1 style={{ fontSize: '1.5rem', fontWeight: 700, marginBottom: 16 }}>Terminmanagement</h1>
       <div
         style={{
           marginBottom: 16,
diff --git a/dashboard/src/clients.tsx b/dashboard/src/clients.tsx
index 10014fc..d396df0 100644
--- a/dashboard/src/clients.tsx
+++ b/dashboard/src/clients.tsx
@@ -15,107 +15,73 @@ import {
   Edit,
 } from '@syncfusion/ej2-react-grids';
 import { DialogComponent } from '@syncfusion/ej2-react-popups';
+import { ButtonComponent } from '@syncfusion/ej2-react-buttons';
 
 // Raumgruppen werden dynamisch aus der API geladen
 
-interface DetailsModalProps {
-  open: boolean;
-  client: Client | null;
-  groupIdToName: Record<string | number, string>;
-  onClose: () => void;
-}
-
-function DetailsModal({ open, client, groupIdToName, onClose }: DetailsModalProps) {
-  if (!open || !client) return null;
+// Details dialog renders via Syncfusion Dialog for consistent look & feel
+function DetailsContent({ client, groupIdToName }: { client: Client; groupIdToName: Record<string | number, string> }) {
   return (
-    <div
-      style={{
-        position: 'fixed',
-        top: 0,
-        left: 0,
-        right: 0,
-        bottom: 0,
-        background: 'rgba(0,0,0,0.3)',
-        zIndex: 1000,
-      }}
-    >
-      <div
-        style={{
-          background: 'white',
-          padding: 0,
-          margin: '100px auto',
-          maxWidth: 500,
-          borderRadius: 12,
-          boxShadow: '0 4px 24px rgba(0,0,0,0.12)',
-        }}
-      >
-        <div style={{ padding: 32 }}>
-          <h3 style={{ fontSize: '1.25rem', fontWeight: 700, marginBottom: 18 }}>Client-Details</h3>
-          <table style={{ width: '100%', borderCollapse: 'collapse', marginBottom: 24 }}>
-            <tbody>
-              {Object.entries(client)
-                .filter(
-                  ([key]) =>
-                    ![
-                      'index',
-                      'is_active',
-                      'type',
-                      'column',
-                      'group_name',
-                      'foreignKeyData',
-                      'hardware_token',
-                    ].includes(key)
-                )
-                .map(([key, value]) => (
-                  <tr key={key}>
-                    <td style={{ fontWeight: 'bold', padding: '6px 8px' }}>
-                      {key === 'group_id'
-                        ? 'Raumgruppe'
-                        : key === 'ip'
-                          ? 'IP-Adresse'
-                          : key === 'registration_time'
-                            ? 'Registriert am'
-                            : key === 'description'
-                              ? 'Beschreibung'
-                              : key === 'last_alive'
-                                ? 'Letzter Kontakt'
-                                : key === 'model'
-                                  ? 'Modell'
-                                  : key === 'uuid'
-                                    ? 'Client-Code'
-                                    : key === "os_version"
-                                      ? 'Betriebssystem'
-                                      : key === 'software_version'
-                                        ? 'Clientsoftware'
-                                        : key === 'macs'
-                                          ? 'MAC-Adressen'
-                                          : key.charAt(0).toUpperCase() + key.slice(1)}
-                      :
-                    </td>
-                    <td style={{ padding: '6px 8px' }}>
-                      {key === 'group_id'
-                        ? value !== undefined
-                          ? groupIdToName[value as string | number] || value
-                          : ''
-                        : key === 'registration_time' && value
-                          ? new Date(
-                              (value as string).endsWith('Z') ? (value as string) : value + 'Z'
-                            ).toLocaleString()
-                          : key === 'last_alive' && value
-                            ? String(value) // Wert direkt anzeigen, nicht erneut parsen
-                            : String(value)}
-                    </td>
-                  </tr>
-                ))}
-            </tbody>
-          </table>
-          <div style={{ textAlign: 'right' }}>
-            <button className="e-btn e-outline" onClick={onClose}>
-              Schließen
-            </button>
-          </div>
-        </div>
-      </div>
+    <div className="e-card-content">
+      <table style={{ width: '100%', borderCollapse: 'collapse' }}>
+        <tbody>
+          {Object.entries(client)
+            .filter(
+              ([key]) =>
+                ![
+                  'index',
+                  'is_active',
+                  'type',
+                  'column',
+                  'group_name',
+                  'foreignKeyData',
+                  'hardware_token',
+                ].includes(key)
+            )
+            .map(([key, value]) => (
+              <tr key={key}>
+                <td style={{ fontWeight: 600, padding: '6px 8px', width: '40%' }}>
+                  {key === 'group_id'
+                    ? 'Raumgruppe'
+                    : key === 'ip'
+                      ? 'IP-Adresse'
+                      : key === 'registration_time'
+                        ? 'Registriert am'
+                        : key === 'description'
+                          ? 'Beschreibung'
+                          : key === 'last_alive'
+                            ? 'Letzter Kontakt'
+                            : key === 'model'
+                              ? 'Modell'
+                              : key === 'uuid'
+                                ? 'Client-Code'
+                                : key === 'os_version'
+                                  ? 'Betriebssystem'
+                                  : key === 'software_version'
+                                    ? 'Clientsoftware'
+                                    : key === 'macs'
+                                      ? 'MAC-Adressen'
+                                      : key.charAt(0).toUpperCase() + key.slice(1)}
+                </td>
+                <td style={{ padding: '6px 8px' }}>
+                  {key === 'group_id'
+                    ? value !== undefined
+                      ? groupIdToName[value as string | number] || String(value)
+                      : ''
+                    : key === 'registration_time' && value
+                      ? new Date(
+                          (value as string).endsWith('Z') ? (value as string) : String(value) + 'Z'
+                        ).toLocaleString()
+                      : key === 'last_alive' && value
+                        ? String(value)
+                        : key === 'macs' && typeof value === 'string'
+                          ? value.replace(/,\s*/g, ', ')
+                          : String(value)}
+                </td>
+              </tr>
+            ))}
+        </tbody>
+      </table>
     </div>
   );
 }
@@ -154,31 +120,38 @@ const Clients: React.FC = () => {
 
   // DataGrid row template für Details- und Entfernen-Button
   const detailsButtonTemplate = (props: Client) => (
-    <div style={{ display: 'flex', gap: '8px' }}>
-      <button
-        className="e-btn e-primary"
-        onClick={() => setDetailsClient(props)}
-        style={{ minWidth: 80 }}
-      >
+    <div style={{ display: 'flex', gap: 8, justifyContent: 'center' }}>
+      <ButtonComponent cssClass="e-primary" onClick={() => setDetailsClient(props)}>
         Details
-      </button>
-      <button
-        className="e-btn e-danger"
+      </ButtonComponent>
+      <ButtonComponent
+        cssClass="e-danger"
         onClick={e => {
+          e.preventDefault();
           e.stopPropagation();
           handleDelete(props.uuid);
         }}
-        style={{ minWidth: 80 }}
       >
         Entfernen
-      </button>
+      </ButtonComponent>
     </div>
   );
 
   return (
-    <div>
-      <div className="flex justify-between items-center mb-4">
-        <h2 className="text-xl font-bold">Client-Übersicht</h2>
+    <div id="dialog-target">
+      <div
+        style={{
+          display: 'flex',
+          alignItems: 'center',
+          justifyContent: 'space-between',
+          marginBottom: 16,
+          gap: 12,
+          flexWrap: 'wrap',
+        }}
+      >
+        <h2 style={{ margin: 0, fontSize: '1.25rem', fontWeight: 700 }}>
+          Client-Übersicht
+        </h2>
         <SetupModeButton />
       </div>
       {groups.length > 0 ? (
@@ -190,7 +163,7 @@ const Clients: React.FC = () => {
             toolbar={['Search', 'Edit', 'Update', 'Cancel']}
             allowSorting={true}
             allowFiltering={true}
-            height={400}
+            height={420}
             editSettings={{
               allowEditing: true,
               allowAdding: false,
@@ -228,17 +201,17 @@ const Clients: React.FC = () => {
                 width="140"
               />
               <ColumnDirective field="uuid" headerText="UUID" allowEditing={false} width="160" />
-              <ColumnDirective field="ip" headerText="IP-Adresse" allowEditing={false} width="80" />
+              <ColumnDirective field="ip" headerText="IP-Adresse" allowEditing={false} width="100" />
               <ColumnDirective
                 field="last_alive"
                 headerText="Last Alive"
                 allowEditing={false}
-                width="120"
+                width="150"
               />
-              <ColumnDirective field="model" headerText="Model" allowEditing={true} width="120" />
+              <ColumnDirective field="model" headerText="Model" allowEditing={true} width="140" />
               <ColumnDirective
                 headerText="Aktion"
-                width="190"
+                width="210"
                 template={detailsButtonTemplate}
                 textAlign="Center"
                 allowEditing={false}
@@ -246,17 +219,31 @@ const Clients: React.FC = () => {
             </ColumnsDirective>
             <Inject services={[Page, Toolbar, Search, Sort, Edit]} />
           </GridComponent>
-          <DetailsModal
-            open={!!detailsClient}
-            client={detailsClient}
-            groupIdToName={groupIdToName}
-            onClose={() => setDetailsClient(null)}
-          />
         </>
       ) : (
-        <div className="text-gray-500">Raumgruppen werden geladen ...</div>
+        <span style={{ color: '#6b7280' }}>Raumgruppen werden geladen ...</span>
       )}
-      {/* DialogComponent für Bestätigung */}
+
+      {/* Details-Dialog */}
+      {detailsClient && (
+        <DialogComponent
+          visible={!!detailsClient}
+          header="Client-Details"
+          showCloseIcon={true}
+          target="#dialog-target"
+          width="560px"
+          close={() => setDetailsClient(null)}
+          footerTemplate={() => (
+            <div style={{ display: 'flex', justifyContent: 'flex-end', gap: 8 }}>
+              <ButtonComponent onClick={() => setDetailsClient(null)}>{'Schließen'}</ButtonComponent>
+            </div>
+          )}
+        >
+          <DetailsContent client={detailsClient} groupIdToName={groupIdToName} />
+        </DialogComponent>
+      )}
+
+      {/* Bestätigungs-Dialog für Löschen */}
       {showDialog && deleteClientId && (
         <DialogComponent
           visible={showDialog}
@@ -264,6 +251,7 @@ const Clients: React.FC = () => {
           content="Möchten Sie diesen Client wirklich entfernen?"
           showCloseIcon={true}
           width="400px"
+          target="#dialog-target"
           buttons={[
             { click: confirmDelete, buttonModel: { content: 'Ja', isPrimary: true } },
             { click: cancelDelete, buttonModel: { content: 'Abbrechen' } },
diff --git a/dashboard/src/components/SetupModeButton.tsx b/dashboard/src/components/SetupModeButton.tsx
index b254cb3..7c84e58 100644
--- a/dashboard/src/components/SetupModeButton.tsx
+++ b/dashboard/src/components/SetupModeButton.tsx
@@ -1,18 +1,21 @@
 import React from 'react';
 import { useNavigate } from 'react-router-dom';
 import { Wrench } from 'lucide-react';
+import { ButtonComponent } from '@syncfusion/ej2-react-buttons';
 
 const SetupModeButton: React.FC = () => {
   const navigate = useNavigate();
   return (
-    <button
-      className="setupmode-btn flex items-center gap-2 px-4 py-2 bg-yellow-200 hover:bg-yellow-300 rounded"
+    <ButtonComponent
+      cssClass="e-warning"
       onClick={() => navigate('/setup')}
       title="Erweiterungsmodus starten"
     >
-      <Wrench size={18} />
-      Erweiterungsmodus
-    </button>
+      <span style={{ display: 'inline-flex', alignItems: 'center', gap: 8 }}>
+        <Wrench size={14.4} />
+        Erweiterungsmodus
+      </span>
+    </ButtonComponent>
   );
 };
 
diff --git a/dashboard/src/dashboard.tsx b/dashboard/src/dashboard.tsx
index 0e820a6..379349f 100644
--- a/dashboard/src/dashboard.tsx
+++ b/dashboard/src/dashboard.tsx
@@ -171,10 +171,12 @@ const Dashboard: React.FC = () => {
 
   return (
     <div>
-      <header className="mb-8 pb-4 border-b-2 border-[#d6c3a6]">
-        <h2 className="text-3xl font-extrabold mb-2">Dashboard</h2>
+      <header style={{ marginBottom: 32, paddingBottom: 16, borderBottom: '2px solid #d6c3a6' }}>
+        <h2 style={{ fontSize: '1.75rem', fontWeight: 800, margin: 0, marginBottom: 8 }}>Dashboard</h2>
       </header>
-      <h3 className="text-lg font-semibold mt-6 mb-4">Raumgruppen Übersicht</h3>
+      <h3 style={{ fontSize: '1.125rem', fontWeight: 600, marginTop: 24, marginBottom: 16 }}>
+        Raumgruppen Übersicht
+      </h3>
       <GridComponent
         dataSource={groups}
         allowPaging={true}
diff --git a/dashboard/src/infoscreen_groups.tsx b/dashboard/src/infoscreen_groups.tsx
index fadf0c3..f7ea008 100644
--- a/dashboard/src/infoscreen_groups.tsx
+++ b/dashboard/src/infoscreen_groups.tsx
@@ -335,7 +335,7 @@ const Infoscreen_groups: React.FC = () => {
 
   return (
     <div id="dialog-target">
-      <h2 className="text-xl font-bold mb-4">{de.title}</h2>
+      <h2 style={{ fontSize: '1.25rem', fontWeight: 700, marginBottom: 16 }}>{de.title}</h2>
       <div
         style={{
           display: 'flex',
diff --git a/dashboard/tailwind.config.cjs b/dashboard/tailwind.config.cjs
deleted file mode 100644
index f065a06..0000000
--- a/dashboard/tailwind.config.cjs
+++ /dev/null
@@ -1,10 +0,0 @@
-module.exports = {
-  content: ['./index.html', './src/**/*.{js,ts,jsx,tsx}'],
-  corePlugins: {
-    preflight: false,
-  },
-  theme: {
-    extend: {},
-  },
-  plugins: [],
-};