body
{background-color: #FF5733;}
h1{text-align: center;}
a{margin-left: 2%;}
article{float:left;width: 90%;height:90%;border-right: double;padding: 1%;}
section{}
aside{width:12%; float:left; padding:1%;}
footer{clear:both;}
table{background-color:#c2c3c3; max-width:240px;}
button{width:40px; margin:1px; border:2px outset; }
button:hover{border: inset #a9a8a8 1px;color:#777575;}
#pantalla{background-color: #e4e3e3; 
    margin:0.5em auto; padding:0 0.25em;
    border:inset 5px; border-radius:4px;
    width:96%;display:inline-block;
    font-family:monospace; font-size:1.2em; letter-spacing:0.20em;}
button.doble{width:80px;}