html { box-sizing: border-box; }
*, *:before, *:after { box-sizing: inherit; }
body {
	font: 16px/1.4 arial, sans-serif;
	color: #333;
	background: #f2f2f2;
	}
h1, h2, h3, h4, h5, h6 { color: #036; }
.topo_header  {
	background: #025aa0;
	padding: 5px 20px;
}
.topo_header h1  {
	font-size: 36px;
	margin: 4px 0 2px 0;
	}
.topo_header a  {
	color: #fff;
	text-decoration: none;
	}
.topo_header h2 {
	font-size: 20px;
	margin: 2px 0 4px 0;
	color: #fff;
	}
.principal {
	width: 100%;
	max-width: 728px;
	margin: 0 auto;
	padding: 1px 15px 25px;
	background: #fff;
	}
main h1 {
	margin-top: 0;
	text-align: center;
}
.rodape {
	background: #036;
	color: #fff;
	padding: 5px 0;
	text-align: center;	
	}
pre { font-size: 14px;}
hgroup h1 {text-align: center;}
ul {list-style:none;}
nav {
	background: #bee6ca;
	overflow: auto;
}
nav ul {
	display:flex;
	justify-content: center;
	margin:0;
	padding: 0;
}

nav ul li {
	list-style:none;
	float:left;
	text-align:center;
}
nav a {
		display:block; 
		padding: 5px 10px;
}
nav a:link, nav a:visited{
	color: #000;
	text-decoration: none;
}
nav a:hover{
	color: #fff;
	background: #025aa0;
	text-decoration: none;
}
.alerta {color: orange; font-size: 20px; font-weight: bold;}
.alerta > span {font-size: 40px; vertical-align:middle;}
/* margem dos botões siga-me */
#atftbx > p {margin: 5px 0 0;}