nav{
    display:flex;
    flex-wrap:wrap;
    justify-content: center;
}

nav span{
    flex-basis:100%;
    justify-content: center;
    text-align:center;
}

nav span img {
    width: 400px;
    margin-top: 200px;
}

nav form{
    text-align:center;
}

nav form input[type="text"]{
    width:500px;
    padding:10px;
    margin-bottom:30px;

}

@media all and (max-width:414px){
    nav span img{
        width:200px;
    }

    nav form input[type="text"]{
        border:1px solid #e3e3e3;
        width:260px;
        left:0;
    }

    nav form input[type="submit"]{
        border:1px solid #e8e8e8;
    }
}