body {
 background: url(../picture/33.jpg);
 background-attachment: fixed;
 background-position: center;
 background-size: cover;
 /*background-size: contain*/;
 }
header { color: #00ffff;
 line-height: 1.2;
 margin-bottom: 21px;
}
a { text-shadow: 1px 0px 1px #e0ffff,
 1px 0px 2px #e0ffff,
 1px 0px 6px #e0ffff;
 font-weight: bold;
 font-size: 31px;
 text-align: center;
}
nav { text-align: center;
 margin-bottom: 21px;
}
div { margin-top: 798px;
 text-align: center;
}