CSS实现Bubble提示框

.tip-bubble {
position: relative;
background-color: #202020;
width: 100px;
padding: 20px;
color: #CCC;
text-align: center;
border-radius: 10px;
margin: 50px;
border: 1px solid #111;
box-shadow: 1px 1px 2px #202020;
-moz-box-shadow: 1px 1px 2px #202020;
-webkit-border-shadow: 1px 1px 2px #202020;
text-shadow: 0px 0px 15px #fff;
}

.tip-bubble:after {
content: ”;
position: absolute;
width: 0;
height: 0;
border: 15px solid;
}
.tip-bubble-top:after {
border-bottom-color: #202020;
left: 50%;
bottom: 100%;
margin-left: -15px;
}
.tip-bubble-right:after {
border-left-color: #202020;
left: 100%;
top: 50%;
margin-top: -15px;
}
.tip-bubble-bottom:after {
border-top-color: #202020;
top: 100%;
left: 50%;
margin-left: -15px;
}
.tip-bubble-left:after {
border-right-color: #202020;
top: 50%;
right: 100%;
margin-top: -15px;
}