<!DOCTYPE HTML> <html> <head> <meta charset="utf-8"> <title>{{page_title}}</title> <meta name="viewport" content="width=device-width, initial-scale=1.0"> </head> <body> <style type="text/css"> html, body, #container { height: 100%; } body, #container { overflow: hidden; margin: 0; } #iframe { width: 100%; height: 100%; border: none; } </style> <div id="container"> <iframe id="iframe" sandbox="allow-scripts" src="{{file_url}}"></iframe> </div> </body> </html>