.demo{
    height:150px;
    width:800px;
    background-color: fuchsia;

}

.border{
    height: 200px;
    width: 700px;
    background-image: url(band.jpeg);
    background-repeat: no-repeat;
    background-size: 700px 200px;
}

.main{
    height: 900px;
    width: 700px;
    background-color: lawngreen;
    
    
 
    
    
}

.bottom{
    height:50px;
    width:700px;
    background-color: deepskyblue;
    
}



@media screen and (min-width:800px){.main {
    height: 900px;
    width: 700px;
    background-color: fuchsia;
    }}
    
    @media screen and (min-width:800px){.demo {
    height: 150px;
    width: 800px;
        background-color:deepskyblue;}}
      
        
     
        @media screen and (min-width:800px){.bottom{
            height: 50px;
            width: 700px;
            background-color: orangered;
            }}
        
        @media screen and (min-width:800px){.border{
            height: 200px;
            width: 700px;
            background-color: lawngreen;
            }}