Css Grid и BEM (БЭМ) Позиционирование

.header 
{ 
  display: grid; 
  grid-template: 50px / 100px 1fr; 
} 
 
.logo 
{ 
  grid-area: 1 / 1 / span 1 / span 1; 
} 
 
.menu 
{ 
  grid-area: 1 / 2 / span 1 / span 1; 
}

<div class="header"> 
    
  <h1 class="logo"></h1> 
   
  <nav class="menu"></nav> 
   
</div>

.header 
{ 
  display: grid; 
  grid-template: 50px / 100px 1fr; 
} 
 
.header_logo 
{ 
  grid-area: 1 / 1 / span 1 / span 1; 
} 
 
.logo 
{ 
     
} 
     
.header_menu 
{ 
  grid-area: 1 / 2 / span 1 / span 1; 
} 
 
.menu 
{ 
       
}

<div class="header"> 
        
   <h1 class="logo header_logo"></h1> 
       
   <nav class="menu header_menu"></nav> 
       
</div>