* {
  font-family: Arial, Helvetica, sans-serif;
}


body, html {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  overflow: hidden;
}

.frame-container {
  padding: 0;
  margin: 0;
  overflow: hidden;
  
}

  .frame-container:not(.active) {
      display: none;
  }

  .frame-container .active {
      display: block;
  }




main {
  text-align: center;
}

h1 {
  font-size: 3.5em;
}