#ctt header h1 {
    position: absolute;
    font-size: 0;
    line-height: 0;
    overflow: hidden;
}


#ctt_con .item_content .top_v img{display:none;}
#ctt_con .item_content .top_v img:nth-child(1){display:block; margin:0 auto}

@media screen and (max-width:450px){
   #ctt_con .item_content .top_v img:nth-child(1){display:none;}
   #ctt_con .item_content .top_v img:nth-child(2){display:block; width: 100%;}

   .youtube_box .edge_title{font-size: 30px;}
   .youtube_box .edge_sub_title{font-size: 14px; padding: 10px 10px 50px;}
   .youtube_box .youtube_play iframe{width: 340px !important;}
   .youtube_box > a{font-size: 20px;}
}