js"></script>
    <style amp-custom>
        @font-face {
          font-family: "Open Sans";
          src: url("/fonts/OpenSans-Regular-webfont.woff2") format("woff2"),
              url("/fonts/OpenSans-Regular-webfont.woff") format("woff");
        }
        .sizer {
          height: 100vh;
        }
        h1 {
          font-family: "Open Sans";
        }

    </style>
  </head>
  <body>
    <div class="sizer"></div>
    <h1>Hello AMPHTML World!</h1>
  </body>
</html>
