<!DOCTYPE html>
<html>
    <head>
        <title>Be right back.</title>

        <style>
            html, body {
                height: 100%;
            }

            body {
                margin: 0;
                padding: 0;
                width: 100%;
                color: #B0BEC5;
                display: table;
                font-weight: 100;
                font-family: font-family: system, -apple-system, ".SFNSText-Regular", "San Francisco", "Roboto", "Segoe UI", "Helvetica Neue", "Lucida Grande", sans-serif;
            }

            .container {
                text-align: center;
                display: table-cell;
                vertical-align: middle;
            }

            .content {
                text-align: center;
                display: inline-block;
            }

            .title {
                font-size: 72px;
                margin-bottom: 40px;
            }
        </style>
    </head>
    <body>
        <div class="container">
            <div class="content">
                <div class="title">The site is temporarily unavailable (503).</div>
            </div>
        </div>
    </body>
</html>

<!DOCTYPE html>
<html>
    <head>
        <title>Be right back.</title>

        <link href="https://fonts.googleapis.com/css?family=Lato:100" rel="stylesheet" type="text/css">

        <style>
            html, body {
                height: 100%;
            }

            body {
                margin: 0;
                padding: 0;
                width: 100%;
                color: #B0BEC5;
                display: table;
                font-weight: 100;
                font-family: 'Lato';
            }

            .container {
                text-align: center;
                display: table-cell;
                vertical-align: middle;
            }

            .content {
                text-align: center;
                display: inline-block;
            }

            .title {
                font-size: 72px;
                margin-bottom: 40px;
            }
        </style>
    </head>
    <body>
        <div class="container">
            <div class="content">
                <div class="title">Be right back.</div>
            </div>
        </div>
    </body>
</html>

--- 
+++ 
@@ -2,8 +2,6 @@
 <html>
     <head>
         <title>Be right back.</title>
-
-        <link href="https://fonts.googleapis.com/css?family=Lato:100" rel="stylesheet" type="text/css">
 
         <style>
             html, body {
@@ -17,7 +15,7 @@
                 color: #B0BEC5;
                 display: table;
                 font-weight: 100;
-                font-family: 'Lato';
+                font-family: font-family: system, -apple-system, ".SFNSText-Regular", "San Francisco", "Roboto", "Segoe UI", "Helvetica Neue", "Lucida Grande", sans-serif;
             }
 
             .container {
@@ -40,7 +38,7 @@
     <body>
         <div class="container">
             <div class="content">
-                <div class="title">Be right back.</div>
+                <div class="title">The site is temporarily unavailable (503).</div>
             </div>
         </div>
     </body>
Remove webfont from 503 page
