body {
    max-width: 800px; 
    width: 90%; 
    /* in relation to the viewport */
    margin-left: auto; margin-right: auto;
}

    @media (min-width: 640px) {
        body {
          background-color: #eaf6ff;
}
}


h1 {
    font-size: 2rem;
}

    @media (max-width: 500px) {
        h1 {font-size: 1.5rem;
    }
    }
    @media (min-width: 640px) {
        h1 {font-size: 2.5rem;
        }
    
}

 
#fixed-size-grid-items aside {
    width: 170px; 
    margin: 10px; 
    font-size: 0.8rem; 
   
} 

#fixed-size-grid-items ul {
    display: flex;
    flex-wrap: wrap;
    font-size: .8rem; 
    padding: 0px; 
    
}

#fixed-size-grid-items ul li {
    display: block; 
}





#stretchable-grid-items aside {
    margin: 10px; 
    font-size: 0.8rem; 
   
} 

#stretchable-grid-items ul {
    display: flex;
    flex-wrap: wrap;
    padding: 0px; 
    margin: -10px 1rem -10px 1rem;  
    
}

#stretchable-grid-items ul li {
    display: block; 
    /* width: 100%;  */
}

    @media (min-width: 480px) {
        li {width: 50%;}
    }

    @media (min-width: 640px) {
        li {width: 25%;}
    }