<!DOCTYPE html>
<style>
@font-face {
  font-family: Ahem;
  src: url(../fonts/Ahem.ttf);
}
* {
  font-family: Ahem;
}
</style>
<body style="margin: 0">
  <div style="width: 100px; height: 100px; background: green">
  </div>
</body>