diff --git a/app/webui/accounts-detail.html b/app/webui/accounts-detail.html
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+<!doctype html>
+<html lang="de">
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>CRM – Account Detail</title>
+
+    <script src="https://cdn.tailwindcss.com"></script>
+    <link rel="stylesheet" href="/css/app.css" />
+    <script defer src="https://cdn.jsdelivr.net/npm/alpinejs@3.14.1/dist/cdn.min.js"></script>
+
+    <script type="module" src="/js/store.js"></script>
+    <script type="module" src="/js/components/notifications.js"></script>
+</head>
+<body class="min-h-screen bg-slate-50">
+
+<div x-data="toastContainer()" class="crm-toast-container" x-cloak>
+    <template x-for="n in items" :key="n.id">
+        <div class="crm-toast" :class="'toast-' + n.type"
+             @click="dismiss(n.id)" x-text="n.message"></div>
+    </template>
+</div>
+
+<div x-data="{ init: () => Alpine.store('auth').init() }" x-init="init()" class="flex min-h-screen">
+
+    <aside class="crm-sidebar">
+        <div class="px-6 py-4 text-white text-lg font-bold border-b border-slate-700">
+            <a href="/app.html" class="!text-white !border-0">CRM</a>
+        </div>
+        <nav class="mt-2">
+            <a href="/app.html">Dashboard</a>
+            <a href="/accounts.html" class="active">Accounts</a>
+            <a href="/contacts.html">Contacts</a>
+            <a href="/pipeline.html">Pipeline</a>
+            <a href="/activities.html">Activities</a>
+            <a href="/settings-profile.html">Profil</a>
+            <a href="/settings-users.html" x-show="$store.auth.isAdmin">Users (Admin)</a>
+            <a href="/settings-org.html"   x-show="$store.auth.isAdmin">Org (Admin)</a>
+        </nav>
+    </aside>
+
+    <div class="flex-1 flex flex-col">
+        <header class="bg-white border-b border-slate-200 px-6 py-3 flex items-center justify-between">
+            <h1 class="text-xl font-semibold text-slate-800">Account-Detail</h1>
+            <div class="flex items-center gap-3 text-sm">
+                <span class="text-slate-600">
+                    <strong class="text-slate-900"
+                            x-text="$store.auth.user ? $store.auth.user.name : '…'"></strong>
+                </span>
+                <button class="btn-secondary" @click="$store.auth.logout()">Logout</button>
+            </div>
+        </header>
+
+        <main class="flex-1 p-6" x-data="accountDetail()" x-init="init()">
+
+            <!-- Loading -->
+            <div x-show="loading" class="crm-card text-center py-12">
+                <div class="crm-spinner mx-auto"></div>
+                <p class="text-slate-500 mt-2">Lade Account …</p>
+            </div>
+
+            <div x-show="!loading && account">
+                <!-- Header -->
+                <div class="crm-card mb-4">
+                    <div class="flex items-start justify-between flex-wrap gap-2">
+                        <div>
+                            <h2 class="text-2xl font-bold text-slate-900" x-text="account?.name"></h2>
+                            <p class="text-slate-500 text-sm mt-1">
+                                <span class="crm-badge badge-blue" x-text="account?.industry || '–'"></span>
+                                <span class="crm-badge badge-gray ml-1" x-text="account?.size || '–'"></span>
+                                <span class="ml-2">Owner #<span x-text="account?.owner_id"></span></span>
+                            </p>
+                            <p class="text-blue-600 underline mt-2" x-show="account?.website">
+                                <a :href="account?.website" target="_blank" x-text="account?.website"></a>
+                            </p>
+                        </div>
+                        <div class="flex gap-2">
+                            <button @click="openEdit()" class="btn-secondary">Bearbeiten</button>
+                            <button @click="confirmDelete()" class="btn-danger">Löschen</button>
+                        </div>
+                    </div>
+                </div>
+
+                <!-- Tabs -->
+                <div class="flex border-b border-slate-200 mb-4" role="tablist">
+                    <button @click="tab='info'" :class="tabBtn('info')">Info</button>
+                    <button @click="loadContacts()" :class="tabBtn('contacts')">Contacts</button>
+                    <button @click="loadDeals()"   :class="tabBtn('deals')">Deals</button>
+                    <button @click="loadActivities()" :class="tabBtn('activities')">Activities</button>
+                    <button @click="loadNotes()"   :class="tabBtn('notes')">Notes</button>
+                </div>
+
+                <!-- Info -->
+                <div x-show="tab === 'info'" class="crm-card">
+                    <dl class="grid grid-cols-2 gap-4 text-sm">
+                        <div><dt class="text-slate-500">Name</dt><dd class="font-medium" x-text="account?.name"></dd></div>
+                        <div><dt class="text-slate-500">Branche</dt><dd x-text="account?.industry || '–'"></dd></div>
+                        <div><dt class="text-slate-500">Größe</dt><dd x-text="account?.size || '–'"></dd></div>
+                        <div><dt class="text-slate-500">Website</dt><dd x-text="account?.website || '–'"></dd></div>
+                        <div><dt class="text-slate-500">Org-ID</dt><dd x-text="account?.org_id"></dd></div>
+                        <div><dt class="text-slate-500">Owner</dt><dd x-text="account?.owner_id"></dd></div>
+                        <div><dt class="text-slate-500">Erstellt</dt><dd x-text="formatDateTime(account?.created_at)"></dd></div>
+                        <div><dt class="text-slate-500">Aktualisiert</dt><dd x-text="formatDateTime(account?.updated_at)"></dd></div>
+                    </dl>
+                </div>
+
+                <!-- Contacts -->
+                <div x-show="tab === 'contacts'" class="crm-card">
+                    <div x-show="loadingSub" class="text-center py-4">
+                        <div class="crm-spinner mx-auto"></div>
+                    </div>
+                    <table class="crm-table" x-show="!loadingSub">
+                        <thead><tr><th>Name</th><th>Email</th><th>Phone</th></tr></thead>
+                        <tbody>
+                            <template x-for="c in subLists.contacts" :key="c.id">
+                                <tr class="cursor-pointer"
+                                    @click="window.location.href = '/contacts-detail.html?id=' + c.id">
+                                    <td x-text="(c.first_name || '') + ' ' + (c.last_name || '')"></td>
+                                    <td x-text="c.email || '–'"></td>
+                                    <td x-text="c.phone || '–'"></td>
+                                </tr>
+                            </template>
+                            <tr x-show="!loadingSub && subLists.contacts.length === 0">
+                                <td colspan="3" class="text-center text-slate-500 py-3">Keine Contacts.</td>
+                            </tr>
+                        </tbody>
+                    </table>
+                </div>
+
+                <!-- Deals -->
+                <div x-show="tab === 'deals'" class="crm-card">
+                    <div x-show="loadingSub" class="text-center py-4"><div class="crm-spinner mx-auto"></div></div>
+                    <table class="crm-table" x-show="!loadingSub">
+                        <thead><tr><th>Title</th><th>Stage</th><th>Value</th><th>Close</th></tr></thead>
+                        <tbody>
+                            <template x-for="d in subLists.deals" :key="d.id">
+                                <tr>
+                                    <td x-text="d.title"></td>
+                                    <td><span class="crm-badge badge-blue" x-text="d.stage"></span></td>
+                                    <td x-text="formatCurrency(d.value)"></td>
+                                    <td x-text="d.close_date || '–'"></td>
+                                </tr>
+                            </template>
+                            <tr x-show="!loadingSub && subLists.deals.length === 0">
+                                <td colspan="4" class="text-center text-slate-500 py-3">Keine Deals.</td>
+                            </tr>
+                        </tbody>
+                    </table>
+                </div>
+
+                <!-- Activities -->
+                <div x-show="tab === 'activities'" class="crm-card">
+                    <div x-show="loadingSub" class="text-center py-4"><div class="crm-spinner mx-auto"></div></div>
+                    <ul class="divide-y divide-slate-100" x-show="!loadingSub">
+                        <template x-for="a in subLists.activities" :key="a.id">
+                            <li class="py-2 flex items-start gap-3">
+                                <span class="crm-badge badge-blue" x-text="a.type"></span>
+                                <div class="flex-1">
+                                    <p class="text-sm font-medium" x-text="a.subject"></p>
+                                    <p class="text-xs text-slate-500" x-text="a.body || ''"></p>
+                                </div>
+                            </li>
+                        </template>
+                        <li x-show="!loadingSub && subLists.activities.length === 0"
+                            class="text-center text-slate-500 py-3 text-sm">Keine Activities.</li>
+                    </ul>
+                </div>
+
+                <!-- Notes -->
+                <div x-show="tab === 'notes'" class="crm-card">
+                    <div x-show="loadingSub" class="text-center py-4"><div class="crm-spinner mx-auto"></div></div>
+                    <ul class="space-y-2" x-show="!loadingSub">
+                        <template x-for="n in subLists.notes" :key="n.id">
+                            <li class="border-l-4 border-blue-500 pl-3 py-1">
+                                <p class="text-sm" x-text="n.body"></p>
+                                <p class="text-xs text-slate-400" x-text="formatDateTime(n.created_at)"></p>
+                            </li>
+                        </template>
+                        <li x-show="!loadingSub && subLists.notes.length === 0"
+                            class="text-center text-slate-500 py-3 text-sm">Keine Notes.</li>
+                    </ul>
+                </div>
+            </div>
+
+            <!-- Edit modal -->
+            <div x-show="showEdit" x-cloak class="crm-modal-backdrop" @click.self="closeEdit()">
+                <div class="crm-modal p-6">
+                    <h2 class="text-lg font-semibold mb-4">Account bearbeiten</h2>
+                    <form @submit.prevent="submitEdit()">
+                        <div class="mb-3">
+                            <label class="crm-label">Name *</label>
+                            <input type="text" required x-model="editForm.name" class="crm-input" />
+                        </div>
+                        <div class="mb-3">
+                            <label class="crm-label">Website</label>
+                            <input type="text" x-model="editForm.website" class="crm-input" />
+                        </div>
+                        <div class="grid grid-cols-2 gap-3 mb-3">
+                            <div>
+                                <label class="crm-label">Branche</label>
+                                <input type="text" x-model="editForm.industry" class="crm-input" />
+                            </div>
+                            <div>
+                                <label class="crm-label">Größe</label>
+                                <input type="text" x-model="editForm.size" class="crm-input" />
+                            </div>
+                        </div>
+                        <div x-show="editError" class="mb-3 p-2 bg-red-50 text-red-700 text-sm rounded"
+                             x-text="editError"></div>
+                        <div class="flex gap-2 justify-end">
+                            <button type="button" @click="closeEdit()" class="btn-secondary">Abbrechen</button>
+                            <button type="submit" :disabled="saving" class="btn-primary"
+                                    x-text="saving ? 'Speichere …' : 'Speichern'"></button>
+                        </div>
+                    </form>
+                </div>
+            </div>
+        </main>
+    </div>
+</div>
+
+<script>
+    function accountDetail() {
+        return {
+            id: null,
+            account: null,
+            loading: true,
+            tab: 'info',
+            subLists: { contacts: [], deals: [], activities: [], notes: [] },
+            loadingSub: false,
+            showEdit: false,
+            editForm: { name: '', website: '', industry: '', size: '' },
+            editError: '',
+            saving: false,
+
+            async init() {
+                const params = new URLSearchParams(window.location.search);
+                this.id = params.get('id');
+                if (!this.id) { window.location.href = '/accounts.html'; return; }
+                await this.load();
+            },
+
+            async load() {
+                this.loading = true;
+                try {
+                    const { api } = await import('/js/api.js');
+                    this.account = await api.get(`/accounts/${this.id}`);
+                    this.editForm = {
+                        name: this.account.name || '',
+                        website: this.account.website || '',
+                        industry: this.account.industry || '',
+                        size: this.account.size || '',
+                    };
+                } catch (err) {
+                    Alpine.store('notifications').error(err.message || 'Fehler beim Laden.');
+                } finally { this.loading = false; }
+            },
+
+            async loadContacts() {
+                this.tab = 'contacts';
+                this.loadingSub = true;
+                try {
+                    const { api } = await import('/js/api.js');
+                    const r = await api.get(`/contacts/?account_id=${this.id}&limit=200`);
+                    this.subLists.contacts = Array.isArray(r) ? r : (r.items || []);
+                } finally { this.loadingSub = false; }
+            },
+            async loadDeals() {
+                this.tab = 'deals';
+                this.loadingSub = true;
+                try {
+                    const { api } = await import('/js/api.js');
+                    const r = await api.get(`/deals/?account_id=${this.id}&limit=200`);
+                    // Backend may not have account_id filter; client-filter as fallback
+                    const list = Array.isArray(r) ? r : (r.items || []);
+                    this.subLists.deals = list.filter(d => String(d.account_id) === String(this.id));
+                } finally { this.loadingSub = false; }
+            },
+            async loadActivities() {
+                this.tab = 'activities';
+                this.loadingSub = true;
+                try {
+                    const { api } = await import('/js/api.js');
+                    const r = await api.get(`/activities/?account_id=${this.id}&limit=200`);
+                    this.subLists.activities = Array.isArray(r) ? r : (r.items || []);
+                } finally { this.loadingSub = false; }
+            },
+            async loadNotes() {
+                this.tab = 'notes';
+                this.loadingSub = true;
+                try {
+                    const { api } = await import('/js/api.js');
+                    const r = await api.get(`/notes/?parent_type=account&parent_id=${this.id}`);
+                    this.subLists.notes = Array.isArray(r) ? r : (r.items || []);
+                } catch (err) {
+                    // /notes may not be paginated; show empty on error
+                    this.subLists.notes = [];
+                } finally { this.loadingSub = false; }
+            },
+
+            tabBtn(t) {
+                return this.tab === t
+                    ? 'flex-1 py-2 px-4 text-sm font-medium border-b-2 border-blue-600 text-blue-600'
+                    : 'flex-1 py-2 px-4 text-sm font-medium border-b-2 border-transparent text-slate-500 hover:text-slate-700';
+            },
+
+            openEdit()  { this.showEdit = true; this.editError = ''; },
+            closeEdit() { this.showEdit = false; },
+            async submitEdit() {
+                this.saving = true;
+                this.editError = '';
+                try {
+                    const { api } = await import('/js/api.js');
+                    const payload = { name: this.editForm.name };
+                    if (this.editForm.website) payload.website = this.editForm.website;
+                    if (this.editForm.industry) payload.industry = this.editForm.industry;
+                    if (this.editForm.size) payload.size = this.editForm.size;
+                    await api.patch(`/accounts/${this.id}`, payload);
+                    Alpine.store('notifications').success('Account aktualisiert.');
+                    this.showEdit = false;
+                    await this.load();
+                } catch (err) {
+                    this.editError = err.message || 'Fehler beim Speichern.';
+                } finally { this.saving = false; }
+            },
+
+            async confirmDelete() {
+                if (!confirm('Account wirklich löschen (Soft-Delete)?')) return;
+                try {
+                    const { api } = await import('/js/api.js');
+                    await api.del(`/accounts/${this.id}`);
+                    Alpine.store('notifications').success('Account gelöscht.');
+                    window.location.href = '/accounts.html';
+                } catch (err) {
+                    Alpine.store('notifications').error(err.message || 'Löschen fehlgeschlagen.');
+                }
+            },
+
+            formatCurrency(v) {
+                return Number(v || 0).toLocaleString('de-DE', { style: 'currency', currency: 'EUR', maximumFractionDigits: 0 });
+            },
+            formatDateTime(iso) {
+                if (!iso) return '–';
+                try { return new Date(iso).toLocaleString('de-DE'); } catch { return iso; }
+            },
+        };
+    }
+</script>
+</body>
+</html>
