diff --git a/index.html b/index.html
index 63231bd..197e7e5 100644
--- a/index.html
+++ b/index.html
@@ -35,6 +35,11 @@
         </div>
         <p class="subtitle">Generate custom 3D printable cell holders with STEP export</p>
 
+        <div class="warning-banner">
+            <svg class="warning-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M10.29 3.86L1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z"/><line x1="12" y1="9" x2="12" y2="13"/><line x1="12" y1="17" x2="12.01" y2="17"/></svg>
+            <span>This project is under construction and has many bugs! Always check your parameters and the DXF and STEP files twice!</span>
+        </div>
+
         <div class="main-layout">
             <div class="config-sidebar">
                 <nav class="sidebar-tabs" role="tablist" data-tabs>
diff --git a/styles/main.css b/styles/main.css
index decf0d8..f690b73 100644
--- a/styles/main.css
+++ b/styles/main.css
@@ -95,6 +95,31 @@ h1:hover {
     text-decoration: underline;
 }
 
+.warning-banner {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    gap: 10px;
+    margin: 0 auto 18px;
+    padding: 10px 18px;
+    max-width: 700px;
+    background: rgba(234, 179, 8, 0.1);
+    border: 1px solid rgba(234, 179, 8, 0.45);
+    border-radius: 8px;
+    color: #fde68a;
+    font-size: 0.88em;
+    font-weight: 500;
+    text-align: center;
+    line-height: 1.4;
+}
+
+.warning-icon {
+    width: 18px;
+    height: 18px;
+    flex-shrink: 0;
+    color: #fbbf24;
+}
+
 .gitea-link {
     display: inline-flex;
     align-items: center;