html { background-image: url("ladrillo.jpg"); 
background-position: 50% 0%;
background-repeat:repeat;
font-family:sans-serif;}

h1 {text-align:center;
font-size:250%}

a {text-decoration:none;
border:#F3C56D solid 2px;
background-color:lightyellow;
color:orange;
padding:5px;
margin-left:20px;}

a:visited { border: red solid 2px;
background-color:gray; }

a.volver {text-decoration:blink;
border:black 2px solid;
background-color:white;}

ul { list-style-type: none; text-align: center;
line-height: 200%; }

li { display: inline; 
margin-right: 10px;}

img {float:left;
margin-left:30px;
margin-right:30px;}

h2 {margin-bottom:0px;
margin-top:0px;
background-color:gray;}

div {margin-left:20px;
margin-right:20px;
border:black 5px solid;
clear:both;
background-color:#D7D7D7;}

div p {margin-left:10px;
margin-right:10px;}