.shadow-btn {
    background-color: rgb(0, 0, 0);
    color: black;
    font-size: 1.2rem;
    border: none;
    padding: 0.8rem 1.5rem;
    position: relative;
    background-color: #178a00;
}

.shadow-btn::after {
    content: "";
    position: absolute;
    /*z-index: -1;*/
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
    height: 100%;
    border-radius: inherit;
    animation: shadow-pulse 1s infinite;
}

@keyframes shadow-pulse {
    0% {
        box-shadow: 0 0 0 0 rgba(255, 0, 132, 0.8);
    }

    100% {
        box-shadow: 0 0 0 2rem rgba(0, 128, 128, 0);
    }
}