.main {
    border: 3px solid blue;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 5px;
    margin: 0px auto;
}

.main > div {
    margin: 15px;
}

.img > img {
    width: 100%;;
}

.header > h1 {
    font-size: 20px;
}

.form {
    width: 80%;
}

.form > form {
    width: 100%;
}

button {
    width: 100%;
}

@media screen and (min-width: 768px) {
    /* form {
        display: flex;
        flex-direction: column;
        margin: auto;
    } */

    .borda {
        border: 1px solid red;
    }

    .main {
        width: 450px;
    }
}