@media only screen and (max-width: 440px) {
    h1 {
        font-size: 2.5rem;
    }

    main span {
        font-size: 1rem;
    }

    .result button {
        font-size: .7rem;
    }
}

@media only screen and (max-width: 380px) {
    h1 {
        font-size: 2.5rem;
    }

    main span {
        font-size: .75rem;
    }

    .result button {
        font-size: .6rem;
    }
}