* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
body {
    width: 100vw;
}
a {
    text-decoration: none;
    display: flex;
    justify-content: center;
}
img {
    max-width: 100%;
}

img[alt="desktop"] {
    display: none;
}

@media (min-width: 640px) {
    img[alt="desktop"] {
        display: block;
    }
    img[alt="mobile"] {
        display: none;
    }
}