diff --git a/partials/structure/layout_start.php b/partials/structure/layout_start.php
index abcece6..8d8c348 100644
--- a/partials/structure/layout_start.php
+++ b/partials/structure/layout_start.php
@@ -11,6 +11,21 @@ $childGender = $_SESSION['child_gender_summary'] ?? ''; // 'male' | 'female' | '
 if (!in_array($childGender, ['male', 'female', 'mixed'], true)) {
     $childGender = '';
 }
+
+$debugEnabled = defined('APP_DEBUG') && APP_DEBUG === true;
+$debugFiles = [];
+if ($debugEnabled) {
+    $debugDir = __DIR__ . '/../../debug';
+    if (is_dir($debugDir)) {
+        foreach (scandir($debugDir) as $f) {
+            if ($f === '.' || $f === '..') continue;
+            $path = $debugDir . '/' . $f;
+            if (is_file($path)) {
+                $debugFiles[] = $f;
+            }
+        }
+    }
+}
 ?>
 <!doctype html>
 <html lang="de">
@@ -24,3 +39,63 @@ if (!in_array($childGender, ['male', 'female', 'mixed'], true)) {
 </head>
 <body data-auth="<?= isset($_SESSION['user_id']) ? '1' : '0' ?>" data-child-gender="<?= htmlspecialchars($childGender, ENT_QUOTES) ?>">
 <?php tpl('nav', 'structure'); ?>
+
+<?php if ($debugEnabled): ?>
+  <style>
+    .debug-fab { position: fixed; right: 18px; bottom: 18px; z-index: 200; background:#111827; color:#fff; border:none; border-radius: 999px; width: 52px; height:52px; display:flex; align-items:center; justify-content:center; font-size:24px; box-shadow:0 10px 30px rgba(0,0,0,0.2); cursor:pointer; }
+    .debug-modal { position:fixed; inset:0; background: rgba(0,0,0,0.4); display:none; align-items:center; justify-content:center; z-index: 210; padding:16px; }
+    .debug-modal.open { display:flex; }
+    .debug-panel { background:#fff; border-radius: 12px; padding:16px; width: min(90vw, 640px); max-height: 80vh; overflow:auto; box-shadow:0 10px 30px rgba(0,0,0,0.25); }
+    .debug-modal pre { background:#f8fafc; border:1px solid #e5e7eb; padding:10px; border-radius:8px; max-height: 50vh; overflow:auto; white-space: pre-wrap; }
+  </style>
+  <button class="debug-fab" aria-label="Debug öffnen" data-debug-open>🐞</button>
+  <div class="debug-modal" id="debugModal">
+    <div class="debug-panel">
+      <div style="display:flex;justify-content:space-between;align-items:center;gap:8px;">
+        <h3 style="margin:0;">Debug-Logs</h3>
+        <button class="btn ghost" type="button" data-debug-close>✕</button>
+      </div>
+      <?php if (!$debugFiles): ?>
+        <p class="muted">Keine Logs in /debug/ gefunden.</p>
+      <?php else: ?>
+        <form method="get" id="debugForm" style="margin:12px 0;">
+          <label class="label" for="debugSelect">Log auswählen</label>
+          <select class="select" id="debugSelect" name="file">
+            <option value="">-- auswählen --</option>
+            <?php foreach ($debugFiles as $f): ?>
+              <option value="<?= htmlspecialchars($f, ENT_QUOTES) ?>"><?= htmlspecialchars($f, ENT_QUOTES) ?></option>
+            <?php endforeach; ?>
+          </select>
+        </form>
+        <div id="debugContent"><p class="muted">Log auswählen, um Inhalt zu sehen.</p></div>
+      <?php endif; ?>
+    </div>
+  </div>
+  <script>
+    (function(){
+      const openBtn = document.querySelector('[data-debug-open]');
+      const modal = document.getElementById('debugModal');
+      const closeBtn = modal?.querySelector('[data-debug-close]');
+      const select = document.getElementById('debugSelect');
+      const content = document.getElementById('debugContent');
+      if (openBtn && modal) {
+        openBtn.addEventListener('click', ()=> modal.classList.add('open'));
+      }
+      closeBtn?.addEventListener('click', ()=> modal.classList.remove('open'));
+      modal?.addEventListener('click', (e)=>{ if(e.target === modal) modal.classList.remove('open'); });
+      if (select && content) {
+        select.addEventListener('change', ()=>{
+          const file = select.value;
+          if (!file) { content.innerHTML = '<p class="muted">Log auswählen, um Inhalt zu sehen.</p>'; return; }
+          fetch('/debug?file=' + encodeURIComponent(file))
+            .then(r => r.text())
+            .then(html => {
+              // naive extract content from /debug page: we just display raw text
+              content.innerHTML = '<pre>'+html.replace(/</g,'&lt;')+'</pre>';
+            })
+            .catch(()=> content.innerHTML = '<p class="muted">Konnte Log nicht laden.</p>');
+        });
+      }
+    })();
+  </script>
+<?php endif; ?>
