To change the layout according to a resolution, use the CSS Media Screen:
This example below demonstrates that if the browser has a maximum width of 767px it will make the changes justified.
header .contato .mailtopo, header .contato .dados .campo .siga{display:block;}
header .dados-menu ul{display:block;}
header a.menu-mobile {display:none;}
@media screen and (max-width:767px){
header .contato .mailtopo, header .contato .dados .campo .siga{display:none;}
header .dados-menu ul{display:none;}
header a.menu-mobile {display:block;}
}
That is, just create the layout you want for the lower resolution and one for the higher resolution and tell the CSS which display according to the size of the screen.
If you can adjust a class it is better, if it does not, create another TAG and leave it hidden until the resolution changes and you display or hide.
To force mobile resolution (remove the zoom function), use the meta tag
<meta name="viewport" content="width=device-width,initial-scale=1,user-scalable=no"/>
I hope I have helped.