* {
	margin:0;
	padding:0;
}
.f {
	width:100%;
	height:100px;
	background:red;
}
.div {
	width:100%;
	height:100px;
	background:yellow;
}
.div1 {
	width:100%;
	height:1500px;
	background:#393;
	color:#fff;
}
.a {
	position:fixed;
	left:0;
	top:0;
	z-index:100;
	-webkit-animation:searchTop .5s ease-in-out;
	-moz-animation:searchTop .5s ease-in-out;
	animation:searchTop .5s ease-in-out
}
@-webkit-keyframes searchTop {
	0% {
	top:-100px
}
to {
	top:0
}
}@-moz-keyframes searchTop {
	0% {
	top:-100px
}
to {
	top:0
}
}@keyframes searchTop {
	0% {
	top:-100px
}
to {
	top:0
}
}