.markdown-body
{
    position: relative;
    width: 960px;
    background-color: white;
}

/* returnBtn和backTop已放至common.css */
.returnBtn
{
    margin: 0 auto;
    display: flex;
    justify-content: center;
    align-items: center;
}
.return
{
    
    line-height: 40px;
    padding:0px 20px;
    margin-top: 24px;
    text-decoration: none;
    color: black;
    background-color: white;
    border-radius: 40px;
    height: 40px;
    font-size: 16px;
    box-shadow: none;
    transition: all .3s ease;
}
.return:hover
{
    background-color: #f3f3f3;
}
.backTop
{
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 32px;
    position: absolute;
    right: -80px;
    bottom: 0;
    background-color: white;
    width: 64px;
    height: 64px;
    border-radius: 20px;
    box-shadow: none;
    transition: all .3s ease;
}
.backTop:hover{
    background-color: #f3f3f3;
}