i finally fixed it myself by adding this code
.header-main-area{
padding: 20px 0 0;
}
.site-branding{
width: 25%;
}
.hm-header-sidebar{
width: 75%;
}
@media screen and (max-width: 768px) {
.site-branding, .hm-header-sidebar {
float: none;
width: 100%;
}
}