Maket checker

maket-checker.css

BODY:after { 
    content: "";
    
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;

    min-height: 4000px;
    pointer-events: none;
    
    background-image: url(...);
    background-position: center top;
    background-repeat: no-repeat;
    
    opacity: .2;
    mix-blend-mode: difference; 
}
@media ( min-width: 768px ) { 
    BODY:after { 
        background-image: url(...); 
    } 
}
@media ( min-width: 1200px ) { 
    BODY:after { 
        background-image: url(...); 
    } 
}