#btn{
    width: 40px;
    height: 40px;
    display: none;
    position: fixed;
    left: 50%;
    bottom: 40px;
    margin-left: 610px;
    background: url("https://images.cnblogs.com/cnblogs_com/abao0/975461/o_top_bg.png" )no-repeat left top;
}
#btn:hover{
    background: url("https://images.cnblogs.com/cnblogs_com/abao0/975461/o_top_bg.png" )no-repeat left -40px;
}
#blogTitle h1 {
font-size: 30px;
font-weight: bold;
font-family: "Comic Sans MS";
line-height: 0.1em;
margin-top: 20px;
color: #515151;
}

.scrollCls {
    position: fixed;
    top: 0;
    height: 3px;
    background: orange;
    transiton-property: width,background;
    transition-duration: 1s,1s;
    z-index: 99999;
}
h2{
font-size:12px;
}