diff --git a/api/.gitkeep b/api/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/api/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/config/.gitkeep b/config/.gitkeep
index e69de29..8b13789 100644
--- a/config/.gitkeep
+++ b/config/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/config/prod/.gitkeep b/config/prod/.gitkeep
index e69de29..8b13789 100644
--- a/config/prod/.gitkeep
+++ b/config/prod/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/config/prod/db.php b/config/prod/db.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/config/prod/db.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/config/prod/domaindata.php b/config/prod/domaindata.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/config/prod/domaindata.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/config/prod/emailtemplates.php b/config/prod/emailtemplates.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/config/prod/emailtemplates.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/config/prod/settings.php b/config/prod/settings.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/config/prod/settings.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/config/staging/.gitkeep b/config/staging/.gitkeep
index e69de29..8b13789 100644
--- a/config/staging/.gitkeep
+++ b/config/staging/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/config/staging/db.php b/config/staging/db.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/config/staging/db.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/config/staging/domaindata.php b/config/staging/domaindata.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/config/staging/domaindata.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/config/staging/emailtemplates.php b/config/staging/emailtemplates.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/config/staging/emailtemplates.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/config/staging/settings.php b/config/staging/settings.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/config/staging/settings.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/debug/.gitkeep b/debug/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/debug/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/partials/.gitkeep b/partials/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/partials/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/partials/landing/.gitkeep b/partials/landing/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/partials/landing/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/partials/structure/.gitkeep b/partials/structure/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/partials/structure/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/partials/structure/layout_end.php b/partials/structure/layout_end.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/partials/structure/layout_end.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/partials/structure/layout_start.php b/partials/structure/layout_start.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/partials/structure/layout_start.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/partials/structure/matomo.php b/partials/structure/matomo.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/partials/structure/matomo.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/partials/structure/nav.php b/partials/structure/nav.php
new file mode 100644
index 0000000..e5553d8
--- /dev/null
+++ b/partials/structure/nav.php
@@ -0,0 +1 @@
+<?php // TODO
diff --git a/public/.gitkeep b/public/.gitkeep
index e69de29..8b13789 100644
--- a/public/.gitkeep
+++ b/public/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/public/assets/.gitkeep b/public/assets/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/public/assets/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/public/assets/bilder/.gitkeep b/public/assets/bilder/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/public/assets/bilder/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/public/assets/css/.gitkeep b/public/assets/css/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/public/assets/css/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/public/assets/fonts/.gitkeep b/public/assets/fonts/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/public/assets/fonts/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/public/assets/js/.gitkeep b/public/assets/js/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/public/assets/js/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/public/index.php b/public/index.php
new file mode 100644
index 0000000..72c97ed
--- /dev/null
+++ b/public/index.php
@@ -0,0 +1,270 @@
+<?php
+header('Content-Type: text/html; charset=utf-8');
+echo <<<'HTML'
+<!doctype html>
+<html lang="de">
+  <head>
+    <meta charset="utf-8">
+    <title>3D-Druck Materialmatrix</title>
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <script src="https://cdn.tailwindcss.com"></script>
+    <style>
+      body {
+        background: radial-gradient(circle at top, #e2e8f0 0%, #f8fafc 45%, #e2e8f0 90%);
+      }
+      thead th {
+        position: sticky;
+        top: 0;
+        backdrop-filter: blur(4px);
+      }
+      th[data-printer],
+      td[data-printer] {
+        background: rgba(148, 163, 184, 0.05);
+      }
+      #disclaimer {
+        box-shadow: inset 0 1px 0 rgba(148, 163, 184, 0.25);
+      }
+    </style>
+  </head>
+  <body class="bg-slate-100 min-h-screen">
+    <div class="max-w-6xl mx-auto py-6 space-y-6">
+      <header class="flex items-center justify-between gap-4">
+        <div>
+          <h1 class="text-2xl font-bold tracking-tight text-slate-900">3D-Druck Materialmatrix</h1>
+          <p class="text-xs text-slate-500">Schnell prüfen, welche Filamente auf welchen Druckern laufen.</p>
+        </div>
+        <span id="status" class="text-xs text-slate-500"></span>
+      </header>
+
+      <div class="bg-white/80 backdrop-blur rounded-lg shadow flex gap-6 p-4 min-h-[420px]">
+        <!-- Sidebar -->
+        <aside class="w-72 space-y-5 border-r pr-4 border-slate-100">
+          <div>
+            <h2 class="text-sm font-semibold text-slate-700 mb-2">Drucker auswählen</h2>
+            <label class="block text-xs font-medium mb-1 text-slate-600">Einzelansicht</label>
+            <select id="printerSelect" class="w-full border rounded px-2 py-1 mb-2 text-sm">
+              <option value="">– wird geladen –</option>
+            </select>
+            <p class="text-xs text-slate-500">
+              Zeigt die Kompatibilität nur für diesen Drucker.
+            </p>
+          </div>
+
+          <div>
+            <label class="block text-xs font-medium mb-1 text-slate-600">Vergleich (mehrere)</label>
+            <select id="printerCompare" multiple class="w-full border rounded px-2 py-1 h-32 text-sm"></select>
+            <p class="text-xs text-slate-500">
+              Strg/⌘ gedrückt halten, um mehrere zu wählen.
+            </p>
+          </div>
+
+          <div class="text-xs text-slate-400">
+            Tipp: Im Vergleich werden die ausgewählten Drucker rechts als separate Spalten eingefärbt.
+          </div>
+        </aside>
+
+        <!-- Main -->
+        <main class="flex-1 flex flex-col gap-3">
+          <div class="overflow-auto max-h-[70vh] rounded border bg-white" id="tableWrap">
+            <table class="min-w-full text-sm" id="matTable">
+              <thead class="bg-slate-50">
+                <tr id="tableHead">
+                  <th class="px-3 py-2 text-left">Material</th>
+                  <th class="px-3 py-2 text-left">Eigenschaften</th>
+                  <th class="px-3 py-2 text-left">Tg °C</th>
+                  <th class="px-3 py-2 text-left">Düse</th>
+                  <th class="px-3 py-2 text-left">Platte</th>
+                  <th class="px-3 py-2 text-left">Zusatz</th>
+                  <th class="px-3 py-2 text-left">Anwendung</th>
+                  <th class="px-3 py-2 text-left">Kinder</th>
+                  <th class="px-3 py-2 text-left">Emission</th>
+                </tr>
+              </thead>
+              <tbody id="matBody"></tbody>
+            </table>
+          </div>
+
+          <div id="errorBox" class="hidden rounded bg-rose-50 border border-rose-200 text-rose-700 text-sm px-3 py-2"></div>
+
+          <!-- Hinweisblock unten -->
+          <section id="disclaimer" class="mt-2 rounded-lg border border-slate-200 bg-slate-50 p-4 text-xs text-slate-700 leading-snug">
+            <p>
+              <strong>Hinweis:</strong> Dieses Projekt wird privat betrieben und befindet sich im Aufbau.
+              Es sind noch nicht alle Drucker und Materialien eingetragen.
+              Alle Angaben erfolgen nach bestem Wissen, jedoch <u>ohne Gewähr auf Vollständigkeit oder Richtigkeit</u>.
+            </p>
+          </section>
+        </main>
+      </div>
+    </div>
+
+    <script>
+    const API_BASE = './api';
+    const printerSelect = document.getElementById('printerSelect');
+    const printerCompare = document.getElementById('printerCompare');
+    const matBody = document.getElementById('matBody');
+    const tableHead = document.getElementById('tableHead');
+    const statusEl = document.getElementById('status');
+    const errorBox = document.getElementById('errorBox');
+
+    function showError(msg) {
+      errorBox.textContent = msg;
+      errorBox.classList.remove('hidden');
+    }
+    function clearError() {
+      errorBox.classList.add('hidden');
+    }
+
+    async function fetchJSON(url) {
+      const res = await fetch(url);
+      if (!res.ok) throw new Error('HTTP ' + res.status + ' for ' + url);
+      return await res.json();
+    }
+
+    async function loadPrinters() {
+      try {
+        statusEl.textContent = 'Lade Drucker …';
+        const data = await fetchJSON(`${API_BASE}/printers.php`);
+        printerSelect.innerHTML = '';
+        printerCompare.innerHTML = '';
+        if (!data.length) {
+          printerSelect.innerHTML = '<option value="">(keine Drucker gefunden)</option>';
+          statusEl.textContent = 'Keine Drucker gefunden';
+          return;
+        }
+        data.forEach(p => {
+          printerSelect.appendChild(new Option(p.name, p.id));
+          printerCompare.appendChild(new Option(p.name, p.id));
+        });
+        // ersten Drucker anzeigen
+        loadSinglePrinter(data[0].id);
+        statusEl.textContent = 'Drucker geladen';
+      } catch (err) {
+        console.error(err);
+        showError('Konnte Drucker nicht laden. Prüfe public/api/printers.php.');
+      }
+    }
+
+    async function loadSinglePrinter(id) {
+      if (!id) return;
+      clearError();
+      statusEl.textContent = 'Lade Materialien …';
+      try {
+        const data = await fetchJSON(`${API_BASE}/printer-materials.php?id=${id}`);
+        renderTable([data]);
+        statusEl.textContent = 'Fertig';
+      } catch (err) {
+        console.error(err);
+        showError('Konnte Materialien für Drucker nicht laden.');
+        statusEl.textContent = 'Fehler';
+      }
+    }
+
+    async function loadMultiplePrinters(ids) {
+      if (!ids.length) return;
+      clearError();
+      statusEl.textContent = 'Lade Vergleich …';
+      try {
+        const datasets = await Promise.all(ids.map(id => fetchJSON(`${API_BASE}/printer-materials.php?id=${id}`)));
+        renderTable(datasets);
+        statusEl.textContent = 'Vergleich geladen';
+      } catch (err) {
+        console.error(err);
+        showError('Konnte einen der gewählten Drucker nicht laden.');
+        statusEl.textContent = 'Fehler';
+      }
+    }
+
+    function renderTable(datasets) {
+      // Kopf neu aufbauen
+      const baseHead = `
+        <th class="px-3 py-2 text-left">Material</th>
+        <th class="px-3 py-2 text-left">Eigenschaften</th>
+        <th class="px-3 py-2 text-left">Tg °C</th>
+        <th class="px-3 py-2 text-left">Düse</th>
+        <th class="px-3 py-2 text-left">Platte</th>
+        <th class="px-3 py-2 text-left">Zusatz</th>
+        <th class="px-3 py-2 text-left">Anwendung</th>
+        <th class="px-3 py-2 text-left">Kinder</th>
+        <th class="px-3 py-2 text-left">Emission</th>
+      `;
+      let printerCols = '';
+      datasets.forEach(ds => {
+        printerCols += `<th class="px-3 py-2 text-left bg-slate-100" data-printer="${ds.printer.id}">${ds.printer.name}</th>`;
+      });
+      tableHead.innerHTML = baseHead + printerCols;
+
+      const materials = datasets[0]?.materials ?? [];
+      matBody.innerHTML = '';
+
+      materials.forEach((m, idx) => {
+        const tr = document.createElement('tr');
+        tr.className = idx % 2 === 0 ? 'bg-white' : 'bg-slate-50/60';
+
+        const kid = m.kid_safety === 'safe' ? '🌿' : (m.kid_safety === 'limited' ? '🟡' : '🔴');
+        const em  = m.emission === 'low' ? '✅' : (m.emission === 'medium' ? '⚠️' : '⛔');
+
+        let html = `
+          <td class="px-3 py-2 font-medium">${m.code}<div class="text-xs text-slate-500">${m.short_desc ?? ''}</div></td>
+          <td class="px-3 py-2">${m.properties ?? ''}</td>
+          <td class="px-3 py-2">${m.tg_celsius ?? '–'}</td>
+          <td class="px-3 py-2">${m.nozzle_req ?? ''}</td>
+          <td class="px-3 py-2">${m.plate_req ?? ''}</td>
+          <td class="px-3 py-2">${m.extra_req ?? ''}</td>
+          <td class="px-3 py-2">${m.application ?? ''}</td>
+          <td class="px-3 py-2">${kid}</td>
+          <td class="px-3 py-2">${em}</td>
+        `;
+
+        // Drucker-Spalten
+        datasets.forEach(ds => {
+          const match = ds.materials.find(x => x.id === m.id || x.code === m.code);
+          if (!match || !match.support_level) {
+            html += `<td class="px-3 py-2" data-printer="${ds.printer.id}"><span class="px-2 py-1 rounded bg-slate-200 text-xs">unbekannt</span></td>`;
+          } else {
+            let badge = '';
+            if (match.support_level === 'full') {
+              badge = '<span class="px-2 py-1 rounded bg-green-100 text-green-800 text-xs">✓ voll</span>';
+            } else if (match.support_level === 'partial') {
+              badge = '<span class="px-2 py-1 rounded bg-amber-100 text-amber-800 text-xs">⚠ teilw.</span>';
+            } else if (match.support_level === 'with_addon') {
+              badge = '<span class="px-2 py-1 rounded bg-sky-100 text-sky-800 text-xs">⚙ Zusatz</span>';
+            } else {
+              badge = '<span class="px-2 py-1 rounded bg-rose-100 text-rose-800 text-xs">✗ nein</span>';
+            }
+            const note = match.partial_reason
+              ? `<div class="text-xs text-slate-400">${match.partial_reason}</div>`
+              : (match.extra_info ? `<div class="text-xs text-slate-400">${match.extra_info}</div>` : '');
+            html += `<td class="px-3 py-2" data-printer="${ds.printer.id}">${badge}${note}</td>`;
+          }
+        });
+
+        tr.innerHTML = html;
+        matBody.appendChild(tr);
+      });
+    }
+
+    // Events
+    printerSelect.addEventListener('change', e => {
+      const id = e.target.value;
+      if (id) {
+        loadSinglePrinter(id);
+        // Vergleich leeren
+        printerCompare.selectedIndex = -1;
+      }
+    });
+
+    printerCompare.addEventListener('change', e => {
+      const ids = Array.from(e.target.selectedOptions).map(o => o.value);
+      if (ids.length) {
+        loadMultiplePrinters(ids);
+      }
+    });
+
+    // Start
+    loadPrinters();
+    </script>
+  </body>
+</html>
+
+HTML;
diff --git a/src/.gitkeep b/src/.gitkeep
index e69de29..8b13789 100644
--- a/src/.gitkeep
+++ b/src/.gitkeep
@@ -0,0 +1 @@
+
diff --git a/src/README.md b/src/README.md
new file mode 100644
index 0000000..b493024
--- /dev/null
+++ b/src/README.md
@@ -0,0 +1 @@
+# src\n\nTODO: Core backend/business logic.\n
diff --git a/tools/.gitkeep b/tools/.gitkeep
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/tools/.gitkeep
@@ -0,0 +1 @@
+