#custom-convert-button {
    margin: auto;
    display: block;
    margin-top: 20px;
    width: 100%;
}

@media (max-width: 1440px) {
    #custom-convert-button {
        display: block;
    }
}

@media (min-width: 991px) {
    #custom-convert-button {
        margin-top: 3rem;
    }
}