body {
    border-left: solid 10px blue;
}

#base {
    padding-left: 5px;
    border-left: solid 10px red;
}

@keyframes blackWhite {
    0% {
        background-color: rgb(30, 253, 0);
    }
    25% {
        background-color: rgb(30, 253, 0);
    }
    26% {
        background-color: rgb(255, 0, 179);
    }
    50% {
        background-color: rgb(255, 0, 179);
        width: 160px;
        height: 50px;
    }
    51% {
        background-color: rgb(251, 255, 0);
        
    }
    75% {
        background-color: rgb(251, 255, 0);
    }
    76% {
        background-color: rgb(0, 225, 255);
    }
    100% {
        background-color: rgb(0, 225, 255);
        width: calc(130px + 5px);
        height: calc(40px + 5px);
    }
}

button{
    width: 150px;
    height: 30px;
}


button:hover {
    background-color: black;
    animation-name: blackWhite;
    animation-iteration-count: infinite;
    animation-duration: 0.25s;
}