body,html {
background-color: #CCC;
height: 100%;
width: 100%;
margin: 0px;
padding: 0px;
}
#main{
height: 80%;
width: 100%;
}
section{
background: url(cronometro1.png) left top no-repeat;
height: 40%;
margin-left: 2%;
}
section #cronometro{
height: 60%;
margin-left: 2%;
}
section #blanco{
height: 40%;
}
header{
height: 15%;
}
footer{
height: 45%;
}