body {
  background-image: url("background.png");
  background-size: cover;
}
.flex1{
    display: flex;
    justify-content: center;
    margin-bottom: 10px;
}
@media (min-width: 751px) {
  .flex2{
    display: flex;
    justify-content: center;
  } 
}
@media (max-width: 750px) {
  .flex2{
    display: flex;
    flex-direction: column;
    align-items: center;
  } 
}