@media (max-width: 540px) {
    .btn-option {
        padding: 10px;
        font-size: 0.9rem;
    }

    .btn-option .material-icons {
        font-size: inherit;
    }

    .required-fields ul li {
        font-size: 0.9rem;
    }

    .required-fields ul {
        padding-left: 1rem;
    }

    .register-required-fields ul li {
        font-size: 0.9rem;
    }

    .register-required-fields ul {
        padding-left: 1rem;
    }

    .alert {
        font-size: 0.9rem;
        padding: 10px;
    }

    .alert .close {
        font-size: 1rem;
    }
}