@keyframes animate-in {
    0% {
        background-size:  0 2px, 0 0, 0 0, 0 0; 
    }

    25% {
        background-size:  100% 2px, 0 0, 0 0, 0 0; 
    }

    50% {
        background-size:  100% 2px, 2px 100%, 0 0, 0 0; 
    }

    75% {
        background-size:  100% 2px, 2px 100%, 100% 2px, 0 0; 
    }

    100% {
        background-size:  100% 2px, 2px 100%, 100% 2px, 2px 100%;  
    }
}