.nav__list>li.instagram{
    margin: 0 ;
}
.nav__list-instagram{
    width: 16px;
    height: 16px;
}
.footer__instagram{
    width: 100%;
    margin-top: 38px;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    & > a{
        width: 16px;
        height: 16px;
    }
}

@media screen and (min-width: 768px){
    .header__menu{
        & > li{
            &.instagram{
                width:16px;
                height: 16px;
            }
        }
    }
 .footer__instagram{
    justify-content: flex-start;
    & > a{
        width: 18px;
        height: 18px;
    }
 }
}