.topics.alt2 .list {position:relative;width:1200px;height:120px;}
.topics.alt2 .list-item {position:absolute;left:0;top:0;opacity:0;z-index:-1;transition:opacity 1s ease 0s;}
.topics.alt2 .list-item {margin-top:0;}
.topics.alt2 .imgs .startNext,.topics.alt2 .imgs .startPre {opacity:1;z-index:1;}
.topics.alt2 #preBtn2,.topics.alt2 #nextBtn2 {display:none;}