header, footer, main, aside{
	  padding: 15px;
	  margin: 10px;
	  background-color:lightgray;
	  text-align:center;
	  font-family:Arial;
}
.btns{
	margin-top:5px ;
	padding:5px;
	}

aside{
	padding:30px;
	float:left;
}


footer{
 font-weight:bold;
 color:darkblue;
 background:
 url(mathbg.png) center center no-repeat;
 
}


input[type="button"]:hover{
background-color:lightblue;
cursor:pointer;
}


input[type="text"]{
	padding:5px;
	font-size:1em;
	border:1px solid lightgray;
	border-radius:4px;


}


input[type="button"]{
font-weight:bold;
border-style:double;
line-height:30px;
padding-right:10px;
padding-left:10px;
}

ul{
	list-style-type:square;
	list-style-position:inside;
	padding-left:10px;
	
}