html,
body {
  margin: 0;
  padding: 0;
  overflow-x: hidden;
  overflow-y: auto;
}

.main{
  width: 100%;
  min-height: 100vh;
  background-repeat: no-repeat;
  background-position: top center;
  background-size: 100% auto;
}

@keyframes flash {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(.9);
  }
  100% {
    transform: scale(1);
  }
}