.logo{
    position: fixed;
    top: 80px;
    left: 80px;
    z-index: 100;
}

@media (max-width:768px){
    .logo{
        position: fixed;
        top: 30px;
        left: 30px;
        z-index: 100;
        width: 200px;
        height: auto;
    }
}