html { 
  background: url(back.jpg) no-repeat center center fixed; 
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}
body {
	margin:30px 50px;
	font-family: Arial, Helvetica, sans-serif;
	font-size : 20px;
	color: white;
}
.left    { float: left; }
.right   { float: right; }
.cleaner { 	clear:both; }
.stred  { text-align: center; }
.vpravo { text-align: right; }
.vlavo  { text-align: left; }
.center { display: inline-block; }
.slido {
	cursor:pointer;
	background-color:#1a73e8;
	-moz-border-radius:30px;
	-webkit-border-radius:30px;
	border-radius:30px;
	margin-top:30px;
	text-align: center;
	width: 222px;
}
#div { border: 1px solid #F00; }