* {
	padding:0;
	margin:0;
}
.tjt {
	width:200px;
	height:200px;
	border-radius:50%;
	background:linear-gradient(90deg,black 50%,white 50%);
	margin:50px auto;
	position:relative;
	border:2px solid #000;
}
.tjt:before {
	content:" ";
	position:absolute;
	width:0px;
	height:0px;
	padding:25px;
	border:25px solid black;
	border-radius:50%;
	background:white;
	left:50px;
}
.tjt:after {
	content:" ";
	width:0px;
	height:0px;
	padding:25px;
	border:25px solid white;
	border-radius:50%;
	background:black;
	position:absolute;
	left:50px;
	top:100px;
}
.speed {
	text-align:center;
	font-size:20px;
	font-weight:bold;
}