diff --git a/lab/preview.html b/lab/preview.html
new file mode 100644
index 0000000..cdd3ef3
--- /dev/null
+++ b/lab/preview.html
@@ -0,0 +1,283 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<title>Home-Lab diagram – live editor</title>
+<meta name="viewport" content="width=device-width, initial-scale=1">
+<style>
+  :root{--bg:#f7f9fc;--text:#222;--accent:#0d6efd}
+  body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial;font-size:14px;background:var(--bg);color:var(--text)}
+  header{background:var(--accent);color:#fff;padding:.6rem 1rem;font-weight:600;display:flex;gap:.5rem;align-items:center}
+  header button{padding:.2rem .6rem;border:none;border-radius:4px;background:#fff;color:var(--accent);cursor:pointer}
+  .wrap{display:flex;height:calc(100vh - 40px)}
+  .panel{flex:1;display:flex;flex-direction:column;overflow:hidden;border-right:1px solid #ddd;transition:flex .3s ease}
+  .panel:last-child{border:none}
+  h3{margin:.4rem .6rem;font-size:1rem}
+  #src, #preview{flex:1;padding:.5rem;overflow:auto;background:#fff;font-family:"Consolas","Monaco",monospace}
+  #src{border:none;outline:none;background:#1e1e1e;color:#d4d4d4;white-space:pre-wrap}
+  #preview{display:flex;align-items:flex-start;justify-content:center;min-height:0}
+  svg{max-width:100%;height:auto}
+  #error{color:#d32f2f;background:#fff3cd;padding:.5rem;margin:.5rem;border-left:4px solid #d32f2f;display:none}
+  #zoomVal{margin-left:.5rem;font-size:.9rem;color:#fff}
+  /* collapsed state */
+  #srcPanel.collapsed{flex:0}
+  #srcPanel.collapsed #src{display:none}
+</style>
+<!-- ONLY Mermaid – NO Monaco, NO AMD loader -->
+<script src="https://cdn.jsdelivr.net/npm/mermaid@10.6.1/dist/mermaid.min.js"></script>
+</head>
+<body>
+<header>
+  <button id="toggleBtn" onclick="togglePanel()">🗔 Hide source</button>
+  Home-Lab diagram – live Mermaid editor
+  <button onclick="saveSVG()">💾 SVG</button>
+  <button onclick="savePNG()">💾 PNG</button>
+  <button onclick="reset()">🔄 Reset</button>
+  <label style="margin-left:auto;display:flex;align-items:center;gap:.3rem;color:#fff">
+    Zoom: <input type="range" id="zoom" min="50" max="300" value="100" style="width:100px"><span id="zoomVal">100%</span>
+  </label>
+</header>
+
+<div class="wrap">
+  <div class="panel" id="srcPanel">
+    <h3>Source (edit here)</h3>
+    <textarea id="src" spellcheck="false"></textarea>
+  </div>
+  <div class="panel">
+    <h3>Live preview</h3>
+    <div id="preview"></div>
+    <div id="error"></div>
+  </div>
+</div>
+
+<script>
+/* ---------- DEFAULT SOURCE – guaranteed valid Mermaid 10.6.1 ---------- */
+const DEFAULT = `flowchart TD
+%% ---------- styles ----------
+classDef internet fill:#e1f5ff,stroke:#007bff
+classDef router  fill:#fff3cd,stroke:#ffc107
+classDef lan     fill:#f8f9ff,stroke:#6c757d,stroke-width:2px
+classDef core    fill:#ffe6e6,stroke:#dc3545
+classDef infra   fill:#e6ffe6,stroke:#28a745
+classDef worker  fill:#f0e6ff,stroke:#6f42c1
+classDef iot     fill:#fff9e6,stroke:#fd7e14
+
+%% ---------- nodes ----------
+internet(🌐 Internet / Cloud):::internet
+router[🛜 Router\nhub.lan\n192.168.1.1]:::router
+
+subgraph LAN [🏠 LAN 192.168.1.0/24]
+  subgraph CORE [💻 Core server\n192.168.1.159]
+    traefik[🚦 Traefik]:::core
+    gitea[📚 Gitea]:::core
+    dokku[🐳 Dokku]:::core
+    auction[🧱 Auction stack]:::core
+    mi50[🧠 MI50 / Ollama]:::core
+  end
+
+  subgraph INFRA [🧭 Infra & DNS\n192.168.1.163]
+    adguard[🛡️ AdGuard]:::infra
+    artifactory[📦 Artifactory]:::infra
+  end
+
+  ha[🏡 Home Assistant\n192.168.1.193]:::infra
+  atlas[🧱 Atlas\n192.168.1.100]:::worker
+
+  iot1[📺 IoT-1]:::iot
+  iot2[📟 IoT-2]:::iot
+end
+
+subgraph TETHER [📶 Tether 192.168.137.0/24]
+  hermes[🛰️ Hermes]:::worker
+  plato[🛰️ Plato]:::worker
+end
+
+dev[👨‍💻 Dev laptop]:::internet
+
+%% ---------- edges ----------
+internet ==> router
+router --> CORE
+router --> INFRA
+router --> ha
+router --> atlas
+router --> iot1
+router --> iot2
+
+dev ==> gitea
+dev ==> dokku
+dev ==> mi50
+
+traefik --> gitea
+traefik --> auction
+traefik --> dokku
+
+CORE -.->|DNS| adguard
+ha   -.->|DNS| adguard
+atlas-.->|DNS| adguard
+hermes-.->|DNS| adguard
+plato-.->|DNS| adguard
+
+CORE === TETHER
+`;
+
+/* ---------- safe localStorage access ---------- */
+function getStorage(key, fallback) {
+  try {
+    const val = localStorage.getItem(key);
+    return val !== null ? val : fallback;
+  } catch (e) {
+    // IntelliJ preview blocks localStorage
+    console.warn('localStorage unavailable:', e);
+    return fallback;
+  }
+}
+function setStorage(key, val) {
+  try {
+    localStorage.setItem(key, val);
+  } catch (e) {
+    console.warn('localStorage save failed:', e);
+  }
+}
+
+/* ---------- load state ---------- */
+const srcEl = document.getElementById('src');
+const errEl = document.getElementById('error');
+srcEl.value = getStorage('labDiagram', DEFAULT);
+
+const srcPanel = document.getElementById('srcPanel');
+const toggleBtn = document.getElementById('toggleBtn');
+if (getStorage('panelCollapsed', 'false') === 'true') {
+  srcPanel.classList.add('collapsed');
+  toggleBtn.textContent = '🗔 Show source';
+}
+
+/* ---------- panel toggle ---------- */
+function togglePanel() {
+  srcPanel.classList.toggle('collapsed');
+  const collapsed = srcPanel.classList.contains('collapsed');
+  toggleBtn.textContent = collapsed ? '🗔 Show source' : '🗔 Hide source';
+  setStorage('panelCollapsed', collapsed);
+}
+
+/* ---------- Mermaid init ---------- */
+mermaid.initialize({startOnLoad: false, theme: 'default'});
+
+/* ---------- render ---------- */
+function render() {
+  const src = srcEl.value;
+  setStorage('labDiagram', src);
+  showError('');
+  
+  const preview = document.getElementById('preview');
+  preview.innerHTML = '';
+  
+  const mermaidDiv = document.createElement('div');
+  mermaidDiv.className = 'mermaid';
+  mermaidDiv.textContent = src;
+  preview.appendChild(mermaidDiv);
+  
+  // Render then zoom
+  mermaid.init(undefined, mermaidDiv).then(() => {
+    const svg = preview.querySelector('svg');
+    if (svg) {
+      svg.style.maxWidth = 'none';
+      svg.style.width = 'auto';
+      svg.style.height = 'auto';
+      svg.style.transformOrigin = 'top left';
+      applyZoom();
+    }
+  }).catch(e => {
+    showError('Mermaid error: ' + e.message);
+  });
+}
+
+function showError(msg) {
+  errEl.textContent = msg;
+  errEl.style.display = msg ? 'block' : 'none';
+}
+
+/* ---------- auto-render + zoom ---------- */
+srcEl.addEventListener('input', () => {
+  clearTimeout(srcEl._t);
+  srcEl._t = setTimeout(render, 300);
+});
+
+const zoomEl = document.getElementById('zoom');
+zoomEl.addEventListener('input', () => {
+  document.getElementById('zoomVal').textContent = zoomEl.value + '%';
+  applyZoom();
+});
+
+function applyZoom() {
+  const svg = document.querySelector('#preview svg');
+  if (svg) {
+    svg.style.transform = `scale(${zoomEl.value / 100})`;
+  }
+}
+
+/* ---------- actions ---------- */
+function reset() {
+  if (confirm('Reset to default diagram?')) {
+    srcEl.value = DEFAULT;
+    zoomEl.value = 100;
+    document.getElementById('zoomVal').textContent = '100%';
+    setStorage('labDiagram', DEFAULT);
+    render();
+  }
+}
+
+function saveSVG() {
+  const svg = document.querySelector('#preview svg');
+  if (!svg) return alert('Nothing to save yet.');
+  
+  const clone = svg.cloneNode(true);
+  clone.removeAttribute('style');
+  clone.setAttribute('xmlns', 'http://www.w3.org/2000/svg');
+  
+  const blob = new Blob([clone.outerHTML], {type: 'image/svg+xml'});
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement('a');
+  a.href = url;
+  a.download = 'home-lab.svg';
+  a.click();
+  setTimeout(() => URL.revokeObjectURL(url), 100);
+}
+
+function savePNG() {
+  const svg = document.querySelector('#preview svg');
+  if (!svg) return alert('Nothing to save yet.');
+  
+  const bbox = svg.getBBox();
+  const width = Math.max(bbox.width, 1200);
+  const height = Math.max(bbox.height, 800);
+  
+  const svgData = new XMLSerializer().serializeToString(svg);
+  const img = new Image();
+  
+  img.onload = () => {
+    const canvas = document.createElement('canvas');
+    canvas.width = width;
+    canvas.height = height;
+    const ctx = canvas.getContext('2d');
+    
+    ctx.fillStyle = 'white';
+    ctx.fillRect(0, 0, width, height);
+    ctx.drawImage(img, 0, 0, width, height);
+    
+    canvas.toBlob(blob => {
+      const a = document.createElement('a');
+      a.href = URL.createObjectURL(blob);
+      a.download = 'home-lab.png';
+      a.click();
+    });
+  };
+  
+  img.onerror = () => alert('PNG conversion failed. Try SVG instead.');
+  img.src = 'data:image/svg+xml;charset=utf-8,' + encodeURIComponent(svgData);
+}
+
+// Initial render
+render();
+</script>
+</body>
+</html>
\ No newline at end of file
diff --git a/public/index.html b/public/index.html
new file mode 100644
index 0000000..d9ce8b7
--- /dev/null
+++ b/public/index.html
@@ -0,0 +1,264 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<title>Home-Lab diagram – live editor</title>
+<meta name="viewport" content="width=device-width, initial-scale=1">
+<style>
+  :root{--bg:#f7f9fc;--text:#222;--accent:#0d6efd}
+  body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial;font-size:14px;background:var(--bg);color:var(--text)}
+  header{background:var(--accent);color:#fff;padding:.6rem 1rem;font-weight:600;display:flex;gap:.5rem;align-items:center}
+  header button{padding:.2rem .6rem;border:none;border-radius:4px;background:#fff;color:var(--accent);cursor:pointer}
+  .wrap{display:flex;height:calc(100vh - 40px)}
+  .panel{flex:1;display:flex;flex-direction:column;overflow:hidden;border-right:1px solid #ddd;transition:flex .3s ease}
+  .panel:last-child{border:none}
+  h3{margin:.4rem .6rem;font-size:1rem}
+  #src{flex:1;padding:.5rem;overflow:auto;background:#1e1e1e;color:#d4d4d4;font-family:"Consolas","Monaco",monospace;border:none;outline:none;white-space:pre-wrap}
+  #preview{flex:1;padding:.5rem;overflow:auto;background:#fff}
+  /* IMPORTANT: Let the SVG flow naturally and scroll if needed */
+  #preview svg{display:block;margin:0 auto;max-width:100%;height:auto}
+  #error{color:#d32f2f;background:#fff3cd;padding:.5rem;margin:.5rem;border-left:4px solid #d32f2f;display:none}
+  #zoomVal{margin-left:.5rem;font-size:.9rem;color:#fff}
+  /* collapsed state */
+  #srcPanel.collapsed{flex:0}
+  #srcPanel.collapsed #src{display:none}
+  /* Debug: uncomment to see element bounds */
+  /* #preview{outline:2px solid red} #preview svg{outline:2px solid blue} */
+</style>
+<script src="https://cdn.jsdelivr.net/npm/mermaid@10.6.1/dist/mermaid.min.js"></script>
+</head>
+<body>
+<header>
+  <button id="toggleBtn" onclick="togglePanel()">🗔 Hide source</button>
+  Home-Lab diagram – live Mermaid editor
+  <button onclick="saveSVG()">💾 SVG</button>
+  <button onclick="savePNG()">💾 PNG</button>
+  <button onclick="reset()">🔄 Reset</button>
+  <label style="margin-left:auto;display:flex;align-items:center;gap:.3rem;color:#fff">
+    Zoom: <input type="range" id="zoom" min="50" max="300" value="100" style="width:100px"><span id="zoomVal">100%</span>
+  </label>
+</header>
+
+<div class="wrap">
+  <div class="panel" id="srcPanel">
+    <h3>Source (edit here)</h3>
+    <textarea id="src" spellcheck="false"></textarea>
+  </div>
+  <div class="panel">
+    <h3>Live preview</h3>
+    <div id="preview"></div>
+    <div id="error"></div>
+  </div>
+</div>
+
+<script>
+const DEFAULT = `flowchart TD
+%% ---------- styles ----------
+classDef internet fill:#e1f5ff,stroke:#007bff
+classDef router  fill:#fff3cd,stroke:#ffc107
+classDef lan     fill:#f8f9ff,stroke:#6c757d,stroke-width:2px
+classDef core    fill:#ffe6e6,stroke:#dc3545
+classDef infra   fill:#e6ffe6,stroke:#28a745
+classDef worker  fill:#f0e6ff,stroke:#6f42c1
+classDef iot     fill:#fff9e6,stroke:#fd7e14
+
+%% ---------- nodes ----------
+internet(🌐 Internet / Cloud):::internet
+router[🛜 Router\nhub.lan\n192.168.1.1]:::router
+
+subgraph LAN [🏠 LAN 192.168.1.0/24]
+  subgraph CORE [💻 Core server\n192.168.1.159]
+    traefik[🚦 Traefik]:::core
+    gitea[📚 Gitea]:::core
+    dokku[🐳 Dokku]:::core
+    auction[🧱 Auction stack]:::core
+    mi50[🧠 MI50 / Ollama]:::core
+  end
+
+  subgraph INFRA [🧭 Infra & DNS\n192.168.1.163]
+    adguard[🛡️ AdGuard]:::infra
+    artifactory[📦 Artifactory]:::infra
+  end
+
+  ha[🏡 Home Assistant\n192.168.1.193]:::infra
+  atlas[🧱 Atlas\n192.168.1.100]:::worker
+
+  iot1[📺 IoT-1]:::iot
+  iot2[📟 IoT-2]:::iot
+end
+
+subgraph TETHER [📶 Tether 192.168.137.0/24]
+  hermes[🛰️ Hermes]:::worker
+  plato[🛰️ Plato]:::worker
+end
+
+dev[👨‍💻 Dev laptop]:::internet
+
+%% ---------- edges ----------
+internet ==> router
+router --> CORE
+router --> INFRA
+router --> ha
+router --> atlas
+router --> iot1
+router --> iot2
+
+dev ==> gitea
+dev ==> dokku
+dev ==> mi50
+
+traefik --> gitea
+traefik --> auction
+traefik --> dokku
+
+CORE -.->|DNS| adguard
+ha   -.->|DNS| adguard
+atlas-.->|DNS| adguard
+hermes-.->|DNS| adguard
+plato-.->|DNS| adguard
+
+CORE === TETHER
+`;
+
+function getStorage(key, fallback) {
+  try { return localStorage.getItem(key) ?? fallback; } catch { return fallback; }
+}
+function setStorage(key, val) {
+  try { localStorage.setItem(key, val); } catch {}
+}
+
+const srcEl = document.getElementById('src');
+const errEl = document.getElementById('error');
+const zoomEl = document.getElementById('zoom');
+const zoomVal = document.getElementById('zoomVal');
+const srcPanel = document.getElementById('srcPanel');
+const toggleBtn = document.getElementById('toggleBtn');
+
+srcEl.value = getStorage('labDiagram', DEFAULT);
+if (getStorage('panelCollapsed', 'false') === 'true') {
+  srcPanel.classList.add('collapsed');
+  toggleBtn.textContent = '🗔 Show source';
+}
+
+function togglePanel() {
+  srcPanel.classList.toggle('collapsed');
+  const collapsed = srcPanel.classList.contains('collapsed');
+  toggleBtn.textContent = collapsed ? '🗔 Show source' : '🗔 Hide source';
+  setStorage('panelCollapsed', collapsed);
+}
+
+mermaid.initialize({startOnLoad: false, theme: 'default'});
+
+function render() {
+  const src = srcEl.value;
+  setStorage('labDiagram', src);
+  errEl.style.display = 'none';
+  
+  const preview = document.getElementById('preview');
+  preview.innerHTML = '';
+  
+  const mermaidDiv = document.createElement('div');
+  mermaidDiv.className = 'mermaid';
+  mermaidDiv.textContent = src;
+  preview.appendChild(mermaidDiv);
+  
+  // Render and fix sizing
+  mermaid.init(undefined, mermaidDiv).then(() => {
+    const svg = preview.querySelector('svg');
+    if (svg) {
+      // CRITICAL: Ensure SVG has viewBox for proper sizing
+      if (!svg.hasAttribute('viewBox')) {
+        const {width, height} = svg.getBBox();
+        svg.setAttribute('viewBox', `0 0 ${width} ${height}`);
+      }
+      svg.style.maxWidth = '100%';
+      svg.style.height = 'auto';
+      applyZoom();
+    }
+  }).catch(e => {
+    errEl.textContent = 'Mermaid error: ' + e.message;
+    errEl.style.display = 'block';
+  });
+}
+
+srcEl.addEventListener('input', () => {
+  clearTimeout(srcEl._t);
+  srcEl._t = setTimeout(render, 300);
+});
+
+zoomEl.addEventListener('input', () => {
+  zoomVal.textContent = zoomEl.value + '%';
+  applyZoom();
+});
+
+function applyZoom() {
+  const svg = document.querySelector('#preview svg');
+  if (svg) {
+    svg.style.transform = `scale(${zoomEl.value / 100})`;
+  }
+}
+
+function reset() {
+  if (confirm('Reset to default diagram?')) {
+    srcEl.value = DEFAULT;
+    zoomEl.value = 100;
+    zoomVal.textContent = '100%';
+    setStorage('labDiagram', DEFAULT);
+    render();
+  }
+}
+
+function saveSVG() {
+  const svg = document.querySelector('#preview svg');
+  if (!svg) return alert('Nothing to save yet.');
+  
+  const clone = svg.cloneNode(true);
+  clone.removeAttribute('style');
+  clone.setAttribute('xmlns', 'http://www.w3.org/2000/svg');
+  
+  const blob = new Blob([clone.outerHTML], {type: 'image/svg+xml'});
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement('a');
+  a.href = url;
+  a.download = 'home-lab.svg';
+  a.click();
+  setTimeout(() => URL.revokeObjectURL(url), 100);
+}
+
+function savePNG() {
+  const svg = document.querySelector('#preview svg');
+  if (!svg) return alert('Nothing to save yet.');
+  
+  const {width, height} = svg.getBBox();
+  const canvasW = Math.max(width, 1200);
+  const canvasH = Math.max(height, 800);
+  
+  const svgData = new XMLSerializer().serializeToString(svg);
+  const img = new Image();
+  
+  img.onload = () => {
+    const canvas = document.createElement('canvas');
+    canvas.width = canvasW;
+    canvas.height = canvasH;
+    const ctx = canvas.getContext('2d');
+    
+    ctx.fillStyle = 'white';
+    ctx.fillRect(0, 0, canvasW, canvasH);
+    ctx.drawImage(img, 0, 0, canvasW, canvasH);
+    
+    canvas.toBlob(blob => {
+      const a = document.createElement('a');
+      a.href = URL.createObjectURL(blob);
+      a.download = 'home-lab.png';
+      a.click();
+    });
+  };
+  
+  img.onerror = () => alert('PNG conversion failed. Try SVG instead.');
+  img.src = 'data:image/svg+xml;charset=utf-8,' + encodeURIComponent(svgData);
+}
+
+render();
+</script>
+</body>
+</html>
\ No newline at end of file
