h1 { font-size: 1em; }
img.graph {
      width: 24%;
      }

nav { display: none; }
footer {
	border-top-width: 1px;
	border-top-color: black;
	border-top-style: solid;
}

@media only screen and (max-width: 960px){
  img.graph { width: 48%; }
}

@media only screen and (max-width: 640px){
  img.graph { width: 100%; }
   nav { display: block; }

}