<!DOCTYPE html>
<html lang="en">
    <head>
        <!-- Required meta tags -->
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

        <!-- Bootstrap CSS -->
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" integrity="sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M" crossorigin="XXX">

        <link href="XXX" rel="stylesheet" type="text/css" />

        <link href="XXX" rel="stylesheet" type="text/css" />
        <link href="https://use.fontawesome.com/releases/v5.0.6/css/all.css" rel="stylesheet">

        <link href="{{ url_for('static', filename='css/style.css') }}" rel="stylesheet" type="text/css" />

        <style>
            h1 {
                font-size: 234px;
                text-align: center;
                left: 0;
                line-height: 200px;
                margin: auto;
                margin-top: -100px;
                position: absolute;
                top: 50%;
                width: 100%;
            }
        </style>
    </head>
    <body>
        <h1>404</h1>
    </body>
</html>