diff --git a/.dockerignore b/.dockerignore
index 69951f8..80054d0 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -1,8 +1,8 @@
 .git
-.agents
-.codex
 .next
-data
 dist
 node_modules
-npm-debug.log*
+data
+*.db
+.env
+.env.*
diff --git a/Dockerfile b/Dockerfile
index 70e7761..41a08fd 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,12 +1,14 @@
-FROM node:22-bookworm-slim
-
+FROM node:22
 WORKDIR /app
 
-ENV NEXT_TELEMETRY_DISABLED=1
-
-COPY package.json package-lock.json ./
+COPY package*.json ./
 RUN npm ci
 
 COPY . .
+RUN npm run build:api && npm run build:web
 
-EXPOSE 3000 3001
+RUN mkdir -p data && chmod +x scripts/docker-start.sh
+
+EXPOSE 3001
+
+CMD ["sh", "scripts/docker-start.sh"]
diff --git a/scripts/docker-start.sh b/scripts/docker-start.sh
new file mode 100644
index 0000000..bf0d856
--- /dev/null
+++ b/scripts/docker-start.sh
@@ -0,0 +1,16 @@
+#!/bin/sh
+set -e
+
+echo "Running migrations..."
+node scripts/run-migrations.js
+
+echo "Starting API server on :3000..."
+node dist/server/index.js &
+
+echo "Waiting for API..."
+until node -e "require('http').get('http://localhost:3000/health', r => process.exit(r.statusCode===200?0:1)).on('error',()=>process.exit(1))" 2>/dev/null; do
+  sleep 1
+done
+
+echo "Starting Next.js on :3001..."
+exec node_modules/.bin/next start -p 3001
diff --git a/scripts/run-migrations.js b/scripts/run-migrations.js
new file mode 100644
index 0000000..ebbed8a
--- /dev/null
+++ b/scripts/run-migrations.js
@@ -0,0 +1,16 @@
+const { migrate } = require('drizzle-orm/better-sqlite3/migrator');
+const { drizzle } = require('drizzle-orm/better-sqlite3');
+const Database = require('better-sqlite3');
+const fs = require('node:fs');
+const path = require('node:path');
+
+const dataDir = path.resolve('data');
+if (!fs.existsSync(dataDir)) fs.mkdirSync(dataDir, { recursive: true });
+
+const sqlite = new Database(path.join(dataDir, 'leistungsbilanz.db'));
+const db = drizzle(sqlite);
+
+migrate(db, { migrationsFolder: path.resolve('src/db/migrations') });
+sqlite.close();
+
+console.log('Migrations applied');
diff --git a/src/app/globals.css b/src/app/globals.css
index 27b2d63..9c07a40 100644
--- a/src/app/globals.css
+++ b/src/app/globals.css
@@ -1219,3 +1219,68 @@ a.kpi:hover {
     max-height: calc(100vh - 5.5rem);
   }
 }
+
+/* ── Seitenleiste: eingeklappter Zustand ─────────────────────────────── */
+
+.app-shell {
+  transition: grid-template-columns 0.18s ease;
+}
+
+.app-shell-collapsed {
+  grid-template-columns: 64px 1fr;
+}
+
+.sidebar {
+  transition: padding 0.18s ease;
+}
+
+.sidebar-brand {
+  display: flex;
+  align-items: flex-start;
+  justify-content: space-between;
+  gap: 8px;
+}
+
+.sidebar-toggle {
+  background: rgba(255, 255, 255, 0.08);
+  border: 0;
+  border-radius: 6px;
+  color: #fff;
+  cursor: pointer;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+  font-size: 0.8rem;
+  line-height: 1;
+  width: 26px;
+  height: 26px;
+}
+
+.sidebar-toggle:hover {
+  background: rgba(255, 255, 255, 0.18);
+}
+
+.sidebar-collapsed .sidebar-brand {
+  padding: 16px 10px;
+  flex-direction: column;
+  align-items: center;
+}
+
+.sidebar-collapsed .sidebar-brand-text {
+  display: none;
+}
+
+.sidebar-collapsed .sidebar-nav {
+  padding: 12px 8px;
+}
+
+.sidebar-collapsed .sidebar-link {
+  justify-content: center;
+  padding: 10px;
+}
+
+.sidebar-collapsed .sidebar-section-label,
+.sidebar-collapsed .sidebar-label {
+  display: none;
+}
diff --git a/src/app/projects/page.tsx b/src/app/projects/page.tsx
index 93a2d14..21409fd 100644
--- a/src/app/projects/page.tsx
+++ b/src/app/projects/page.tsx
@@ -14,6 +14,7 @@ import type {
   CreateGlobalDeviceInput,
   GlobalDeviceDto,
 } from "../../frontend/types";
+import { GzfPickerModal } from "../../frontend/components/gzf-picker-modal";
 
 const PROJECTS_CHANGED_EVENT = "leistungsbilanz:projects-changed";
 
@@ -67,6 +68,7 @@ export default function ProjectsPage() {
     id: string;
     name: string;
   } | null>(null);
+  const [isGzfPickerOpen, setIsGzfPickerOpen] = useState(false);
 
   async function loadData() {
     setError(null);
@@ -380,18 +382,28 @@ export default function ProjectsPage() {
                 }
               />
             </div>
-            <div className="col-6 col-md-1">
-              <input
-                className="form-control"
-                type="number"
-                step="0.01"
-                min="0"
-                max="1"
-                value={globalDeviceForm.demandFactor}
-                onChange={(event) =>
-                  setGlobalDeviceForm((current) => ({ ...current, demandFactor: event.target.value }))
-                }
-              />
+            <div className="col-6 col-md-2">
+              <div className="input-group">
+                <input
+                  className="form-control"
+                  type="number"
+                  step="0.01"
+                  min="0"
+                  max="1"
+                  value={globalDeviceForm.demandFactor}
+                  onChange={(event) =>
+                    setGlobalDeviceForm((current) => ({ ...current, demandFactor: event.target.value }))
+                  }
+                />
+                <button
+                  className="btn btn-outline-primary"
+                  onClick={() => setIsGzfPickerOpen(true)}
+                  title="Gleichzeitigkeitsfaktor nach AMEV wählen"
+                  type="button"
+                >
+                  AMEV
+                </button>
+              </div>
             </div>
             <div className="col-6 col-md-1">
               <select
@@ -505,6 +517,16 @@ export default function ProjectsPage() {
         </div>
       </section>
       </div>
+
+      {isGzfPickerOpen ? (
+        <GzfPickerModal
+          onClose={() => setIsGzfPickerOpen(false)}
+          onSelect={(value) => {
+            setGlobalDeviceForm((current) => ({ ...current, demandFactor: String(value) }));
+            setIsGzfPickerOpen(false);
+          }}
+        />
+      ) : null}
     </main>
   );
 }
diff --git a/src/frontend/components/AppShell.tsx b/src/frontend/components/AppShell.tsx
index ba08175..bbfa0ae 100644
--- a/src/frontend/components/AppShell.tsx
+++ b/src/frontend/components/AppShell.tsx
@@ -1,21 +1,36 @@
 "use client";
 
+import { useEffect, useState } from "react";
 import { usePathname } from "next/navigation";
 import { Sidebar } from "./Sidebar";
 
 const PROJECT_AREA_PATTERN = /^\/projects(\/[^/]+)?$/;
+const SIDEBAR_COLLAPSED_STORAGE_KEY = "leistungsbilanz:sidebar-collapsed";
 
 export function AppShell({ children }: { children: React.ReactNode }) {
   const pathname = usePathname();
   const showSidebar = PROJECT_AREA_PATTERN.test(pathname ?? "");
+  const [isSidebarCollapsed, setIsSidebarCollapsed] = useState(false);
+
+  useEffect(() => {
+    setIsSidebarCollapsed(window.localStorage.getItem(SIDEBAR_COLLAPSED_STORAGE_KEY) === "1");
+  }, []);
+
+  function toggleSidebarCollapsed() {
+    setIsSidebarCollapsed((current) => {
+      const next = !current;
+      window.localStorage.setItem(SIDEBAR_COLLAPSED_STORAGE_KEY, next ? "1" : "0");
+      return next;
+    });
+  }
 
   if (!showSidebar) {
     return <>{children}</>;
   }
 
   return (
-    <div className="app-shell">
-      <Sidebar />
+    <div className={isSidebarCollapsed ? "app-shell app-shell-collapsed" : "app-shell"}>
+      <Sidebar isCollapsed={isSidebarCollapsed} onToggleCollapsed={toggleSidebarCollapsed} />
       <div className="app-shell-content">{children}</div>
     </div>
   );
diff --git a/src/frontend/components/Sidebar.tsx b/src/frontend/components/Sidebar.tsx
index f1c0dbc..f58c4f6 100644
--- a/src/frontend/components/Sidebar.tsx
+++ b/src/frontend/components/Sidebar.tsx
@@ -14,7 +14,12 @@ const PROJECT_SECTIONS = [
   { id: "projektgeraete", label: "Projektgeräte", icon: "⚙" },
 ] as const;
 
-export function Sidebar() {
+interface SidebarProps {
+  isCollapsed: boolean;
+  onToggleCollapsed: () => void;
+}
+
+export function Sidebar({ isCollapsed, onToggleCollapsed }: SidebarProps) {
   const pathname = usePathname();
   const projectMatch = pathname?.match(/^\/projects\/([^/]+)$/);
   const activeProjectId = projectMatch ? projectMatch[1] : null;
@@ -66,19 +71,31 @@ export function Sidebar() {
   }, [activeProjectId]);
 
   return (
-    <aside className="sidebar">
+    <aside className={isCollapsed ? "sidebar sidebar-collapsed" : "sidebar"}>
       <div className="sidebar-brand">
-        <div className="sidebar-wordmark">Leistungsbilanz</div>
-        <div className="sidebar-bar" />
-        <div className="sidebar-tag">Stromkreis- &amp; Lastberechnung</div>
+        <div className="sidebar-brand-text">
+          <div className="sidebar-wordmark">Leistungsbilanz</div>
+          <div className="sidebar-bar" />
+          <div className="sidebar-tag">Stromkreis- &amp; Lastberechnung</div>
+        </div>
+        <button
+          aria-label={isCollapsed ? "Seitenleiste ausklappen" : "Seitenleiste einklappen"}
+          className="sidebar-toggle"
+          onClick={onToggleCollapsed}
+          title={isCollapsed ? "Seitenleiste ausklappen" : "Seitenleiste einklappen"}
+          type="button"
+        >
+          {isCollapsed ? "»" : "«"}
+        </button>
       </div>
       <nav className="sidebar-nav">
         <Link
           href="/projects"
           className={pathname === "/projects" ? "sidebar-link active" : "sidebar-link"}
+          title="Alle Projekte"
         >
           <span className="sidebar-icon">▦</span>
-          Alle Projekte
+          <span className="sidebar-label">Alle Projekte</span>
         </Link>
 
         <div className="sidebar-section-label">Projekte</div>
@@ -89,9 +106,10 @@ export function Sidebar() {
             className={
               project.id === activeProjectId ? "sidebar-link active" : "sidebar-link"
             }
+            title={project.name}
           >
             <span className="sidebar-icon">▣</span>
-            {project.name}
+            <span className="sidebar-label">{project.name}</span>
           </Link>
         ))}
         {!projects.length ? (
@@ -108,9 +126,10 @@ export function Sidebar() {
                 key={id}
                 href={`#${id}`}
                 className={activeSection === id ? "sidebar-link active" : "sidebar-link"}
+                title={label}
               >
                 <span className="sidebar-icon">{icon}</span>
-                {label}
+                <span className="sidebar-label">{label}</span>
               </a>
             ))}
           </>
diff --git a/src/frontend/components/gzf-picker-modal.tsx b/src/frontend/components/gzf-picker-modal.tsx
new file mode 100644
index 0000000..5f118a6
--- /dev/null
+++ b/src/frontend/components/gzf-picker-modal.tsx
@@ -0,0 +1,86 @@
+"use client";
+
+import { AMEV_GZF_TABLE } from "../../shared/constants/amev-gzf";
+
+interface GzfPickerModalProps {
+  onClose: () => void;
+  onSelect: (value: number) => void;
+}
+
+function formatFactor(value: number) {
+  return value.toLocaleString("de-DE", { minimumFractionDigits: 2, maximumFractionDigits: 2 });
+}
+
+export function GzfPickerModal({ onClose, onSelect }: GzfPickerModalProps) {
+  return (
+    <>
+      <div aria-modal="true" className="modal fade show d-block" role="dialog" tabIndex={-1}>
+        <div className="modal-dialog modal-lg modal-dialog-centered">
+          <div className="modal-content">
+            <div className="modal-header">
+              <div>
+                <h2 className="modal-title fs-5">Gleichzeitigkeitsfaktor nach AMEV</h2>
+                <p className="text-secondary small mb-0">
+                  Tabelle 3 – Gleichzeitigkeitsfaktoren für Verbrauchergruppen
+                </p>
+              </div>
+              <button
+                aria-label="Schließen"
+                className="btn-close"
+                onClick={onClose}
+                type="button"
+              />
+            </div>
+            <div className="modal-body">
+              <div className="table-responsive">
+                <table className="table table-hover align-middle mb-0">
+                  <thead>
+                    <tr>
+                      <th>Verbrauchergruppe</th>
+                      <th>Bereich</th>
+                      <th className="text-end">Mittelwert</th>
+                      <th className="text-end">Gfges</th>
+                      <th className="text-end">Aktion</th>
+                    </tr>
+                  </thead>
+                  <tbody>
+                    {AMEV_GZF_TABLE.map((entry) => (
+                      <tr key={entry.group}>
+                        <td>{entry.group}</td>
+                        <td>{entry.range}</td>
+                        <td className="text-end">{formatFactor(entry.mean)}</td>
+                        <td className="text-end text-secondary small">
+                          {entry.overallRange ?? "–"}
+                        </td>
+                        <td className="text-end">
+                          <button
+                            className="btn btn-sm btn-primary"
+                            onClick={() => onSelect(entry.mean)}
+                            type="button"
+                          >
+                            Übernehmen
+                          </button>
+                        </td>
+                      </tr>
+                    ))}
+                  </tbody>
+                </table>
+              </div>
+              <p className="text-secondary small mt-3 mb-0">
+                Quelle: AMEV „Planungshilfe für elektrische Leistungsbilanzen", Tabelle 3.
+                Übernommen wird jeweils der Mittelwert Gf1 der angegebenen Bandbreite; „Gfges"
+                ist der alternative Gesamtgleichzeitigkeitsfaktor für Verwaltungsgebäude.
+              </p>
+            </div>
+            <div className="modal-footer">
+              <button className="btn btn-outline-secondary" onClick={onClose} type="button">
+                Abbrechen
+              </button>
+            </div>
+          </div>
+        </div>
+      </div>
+      <div className="modal-backdrop fade show" />
+    </>
+  );
+}
diff --git a/src/frontend/components/project-device-modal.tsx b/src/frontend/components/project-device-modal.tsx
index 1707da9..27c24d0 100644
--- a/src/frontend/components/project-device-modal.tsx
+++ b/src/frontend/components/project-device-modal.tsx
@@ -12,6 +12,7 @@ import {
   circuitGroupCategoryLabels,
   type CircuitGroupCategory,
 } from "../../shared/constants/circuit-group";
+import { GzfPickerModal } from "./gzf-picker-modal";
 
 interface ProjectDeviceModalProps {
   globalDevices: GlobalDeviceDto[];
@@ -34,6 +35,7 @@ export function ProjectDeviceModal({
 }: ProjectDeviceModalProps) {
   const [values, setValues] = useState(() => toFormValues(initialDevice, initialValues));
   const [selectedGlobalDeviceId, setSelectedGlobalDeviceId] = useState("");
+  const [isGzfPickerOpen, setIsGzfPickerOpen] = useState(false);
 
   function update(key: keyof typeof values, value: string) {
     setValues((current) => ({ ...current, [key]: value }));
@@ -63,6 +65,7 @@ export function ProjectDeviceModal({
     (!values.cosPhi.trim() || isNumberInRange(values.cosPhi, 0, 1));
 
   return (
+    <>
     <FormModal
       description={
         initialDevice
@@ -167,15 +170,31 @@ export function ProjectDeviceModal({
           step="0.01"
           value={values.powerPerUnit}
         />
-        <NumberField
-          id="device-simultaneity"
-          label="Gleichzeitigkeitsfaktor"
-          max="1"
-          min="0"
-          onChange={(value) => update("simultaneityFactor", value)}
-          step="0.01"
-          value={values.simultaneityFactor}
-        />
+        <div className="col-12 col-md-6">
+          <label className="form-label" htmlFor="device-simultaneity">
+            Gleichzeitigkeitsfaktor
+          </label>
+          <div className="input-group">
+            <input
+              className="form-control"
+              id="device-simultaneity"
+              max="1"
+              min="0"
+              onChange={(event) => update("simultaneityFactor", event.target.value)}
+              step="0.01"
+              type="number"
+              value={values.simultaneityFactor}
+            />
+            <button
+              className="btn btn-outline-primary"
+              onClick={() => setIsGzfPickerOpen(true)}
+              title="Gleichzeitigkeitsfaktor nach AMEV wählen"
+              type="button"
+            >
+              AMEV
+            </button>
+          </div>
+        </div>
         <NumberField
           id="device-cos-phi"
           label="cos Phi"
@@ -199,6 +218,16 @@ export function ProjectDeviceModal({
         </div>
       </div>
     </FormModal>
+    {isGzfPickerOpen ? (
+      <GzfPickerModal
+        onClose={() => setIsGzfPickerOpen(false)}
+        onSelect={(value) => {
+          update("simultaneityFactor", String(value));
+          setIsGzfPickerOpen(false);
+        }}
+      />
+    ) : null}
+    </>
   );
 }
 
diff --git a/src/shared/constants/amev-gzf.ts b/src/shared/constants/amev-gzf.ts
new file mode 100644
index 0000000..0833091
--- /dev/null
+++ b/src/shared/constants/amev-gzf.ts
@@ -0,0 +1,38 @@
+export interface AmevGzfEntry {
+  group: string;
+  range: string;
+  mean: number;
+  overallRange?: string;
+}
+
+// Quelle: AMEV „Planungshilfe für elektrische Leistungsbilanzen" (rev. 4),
+// Tabelle 3 – Gleichzeitigkeitsfaktoren für Verbrauchergruppen.
+export const AMEV_GZF_TABLE: AmevGzfEntry[] = [
+  { group: "Absaugung, Digestorien", range: "0,7", mean: 0.7 },
+  { group: "Aufzüge/Rolltreppen", range: "0,2 – 0,7", mean: 0.5, overallRange: "0,2" },
+  { group: "Beleuchtungsanlagen", range: "0,7 – 0,8", mean: 0.75, overallRange: "0,4" },
+  { group: "Beleuchtungsanlagen in innenliegenden Räumen", range: "0,7 – 0,9", mean: 0.8 },
+  { group: "IuK-Anlagen", range: "1", mean: 1, overallRange: "1" },
+  { group: "Experimentieranlagen", range: "0,2 – 0,4", mean: 0.3 },
+  { group: "Heizung", range: "0,7 – 1", mean: 0.85 },
+  { group: "Kälteanlagen", range: "0,8 – 1", mean: 0.9, overallRange: "0,4 – 0,5" },
+  { group: "Küchen elektrisch ohne Energieoptimierung", range: "0,3 – 0,7", mean: 0.6 },
+  { group: "Küchen elektrisch mit Energieoptimierung", range: "0,2 – 0,6", mean: 0.4 },
+  { group: "Lastenaufzüge, Krananlagen", range: "0,2", mean: 0.2 },
+  {
+    group: "Lüftungsanlagen, kontrollierte Lüftung",
+    range: "0,7",
+    mean: 0.7,
+    overallRange: "0,4 – 0,5",
+  },
+  {
+    group: "Steckdosen 230 V allg. Verbraucher (100 W/Steckdose)",
+    range: "0,1 – 0,3",
+    mean: 0.2,
+  },
+  { group: "Steckdosen 230 V für IuK (100 W/Steckdose)", range: "0,7 – 0,9", mean: 0.8 },
+  { group: "Steckdosen 400 V (1000 W/Steckdose)", range: "0,1 – 0,5", mean: 0.35 },
+  { group: "Schmutz-, Warmwasserpumpen", range: "0,2 – 0,4", mean: 0.3 },
+  { group: "Umwälzpumpen", range: "0,6 – 1", mean: 0.8 },
+  { group: "Werkstätten", range: "0,2 – 0,4", mean: 0.3 },
+];