diff --git a/src/routes/demo.ts b/src/routes/demo.ts
index e664862..78e968c 100644
--- a/src/routes/demo.ts
+++ b/src/routes/demo.ts
@@ -6,7 +6,26 @@ import logger from "../services/logger.js";
 
 const router = Router();
 
-const WATERMARK_HTML = `<div style="position:fixed;bottom:0;left:0;right:0;background:rgba(52,211,153,0.92);color:#0b0d11;text-align:center;padding:8px;font-family:sans-serif;font-size:12px;font-weight:bold;z-index:999999;letter-spacing:0.3px;">Generated by DocFast — docfast.dev | Upgrade to Pro for clean PDFs</div>`;
+const WATERMARK_HTML = `
+<style>
+  @media print { .docfast-wm-overlay { display:block !important; } }
+  .docfast-wm-overlay {
+    position:fixed; top:0; left:0; width:200vw; height:200vh;
+    z-index:999999; pointer-events:none;
+    display:flex; flex-wrap:wrap; align-content:flex-start;
+    transform:rotate(-35deg); transform-origin:center center;
+    margin-top:-50vh; margin-left:-50vw;
+  }
+  .docfast-wm-tile {
+    width:300px; height:120px;
+    display:flex; align-items:center; justify-content:center;
+    font-family:sans-serif; font-size:18px; font-weight:bold;
+    color:rgba(52,211,153,0.18); letter-spacing:1px;
+    white-space:nowrap; user-select:none;
+  }
+</style>
+<div class="docfast-wm-overlay">${Array(80).fill('<div class="docfast-wm-tile">DEMO — docfast.dev</div>').join("")}</div>
+<div style="position:fixed;bottom:0;left:0;right:0;background:rgba(52,211,153,0.92);color:#0b0d11;text-align:center;padding:8px;font-family:sans-serif;font-size:12px;font-weight:bold;z-index:999999;letter-spacing:0.3px;">Generated by DocFast — docfast.dev | Upgrade to Pro for clean PDFs</div>`;
 
 function injectWatermark(html: string): string {
   if (html.includes("</body>")) {