* {
  box-sizing: border-box;
}


h1 {
  margin: 10px;
}

.box {
  
  transform: translateX(400%);
  transition: transform 1s ease;
}

.box:nth-of-type(even) {
  transform: translateX(-400%);
}

.box.show {
  transform: translateX(0);
}

.box h2 {
  font-size: 45px;
}