body {
  background-image: url('fundocamiseta.png');
  background-repeat: repeat; 
  background-size: contain;
  background-position: top right; 
  height: 100%;
  width: 100%;
  display: flex;
  justify-content: center;
  margin: 0;
}

.center {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-top: 4em;
  max-width: 30%;
  height: auto;
}