.lesson-list{margin-top: 12px;}
.lesson-list .title{height:45px;line-height:50px;font-size:1.4rem;}
.exam{margin-top: 12px;}
.invite,.course-nav{transition: all .6s ease}
.top-50{top: 50px!important}
.exam .top{border-bottom: 1px solid #eee;}