.center {
    margin-top: 100px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

@-webkit-keyframes glow {
    0% {
        box-shadow: 0 0 0 0 #734f8c;
    }

    50% {
        box-shadow: 0 0 10px 0 #734f8c;
    }
}

@keyframes glow {
    0% {
        box-shadow: 0 0 0 0 #734f8c;
    }

    50% {
        box-shadow: 0 0 10px 0 #734f8c;
    }
}

.btn {
    background: none;
    color: inherit;
    font: inherit;
    border: none;
    outline: none;
    cursor: pointer;
    border-radius: 12px;
}

.btn-glow {
    background: #51296e;
    color: #fff;
    font-size: 15px;
    font-weight: 500;
    text-transform: uppercase;
    padding: 12px 20px;
    box-shadow: 0 0 0 0 #51296e;
    -webkit-animation: glow 2s linear infinite;
    animation: glow 5s linear infinite;
}