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

.line-high {
    transform: rotate(-45deg) 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(-45deg) scaleY(0); 
    }

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