.line-wide {
  transform: rotate(45deg) scaleX(1);
  animation-name: change-width;
}

.line-high {
  transform: rotate(-135deg) scaleY(1);
  animation-name: change-height;
}

@keyframes change-width {
  0% {
    transform: rotate(45deg) scaleX(0); 
  }

  100% {
    transform: rotate(45deg) scaleX(1);  
  }
} 

@keyframes change-height {
  0% {
    transform: rotate(-135deg) scaleY(0); 
  }

  100% {
    transform: rotate(-135deg) scaleY(1);  
  }
}