html, body {
  height: 100%;
  margin: 0;
  display: flex;
  justify-content: center; /* Center horizontally */
  align-items: center;    /* Center vertically */
  font-family: "Pixelify Sans", serif;
  font-optical-sizing: auto;
}

div.container {
  display: flex;
  flex-direction: column; /* Stack elements vertically */
  align-items: center;    /* Center elements horizontally */
}

img.center {
   margin: 0 auto;
   display: block;
 }