@media (max-width: 820px) {
    main {
        width: 100%;
    }
}

@media (max-width: 550px) {
    input, select, button {
        width: 150px;
    }

    header h1 {
        font-size: 2rem;
    }

    main h2 {
        font-size: 2.5em;
    }

}

@media (max-width: 360px) {
    input, select, button {
        width: 120px;
    }

}