html, body, .prova {
  width: 100%;
  height: 100%;
  padding: 0;
  margin: 0;
  background: #fff;
}

.prova {
  display:-ms-flexbox;
  -ms-flex-pack:center;
  -ms-flex-align:center;

  display:-moz-box;
  -moz-box-pack:center;
  -moz-box-align:center;

  display:-webkit-box;
  -webkit-box-pack:center;
  -webkit-box-align:center;

  display:box;
  box-pack:center;
  box-align:center;

  font: normal 12px "pt mono";
  color: #333;
}

@font-face {
  font-family: 'PT Mono';
  font-style: normal;
  font-weight: 400;
  src: local('PT Mono'), local('PTMono-Regular'), url(http://themes.googleusercontent.com/static/fonts/ptmono/v2/RTA0Dhj_HESY0h-ax44VkwLUuEpTyoUstqEm5AMlJo4.woff) format('woff');
}