.bigbox{width:100%;height:auto;padding:20px;background-color:#fff}.items{height:180px;border:2px solid #e5e5e5;border-radius:2px;margin-bottom:20px}.item_header{height:40px;border-bottom:2px solid #e5e5e5;border-radius:2px 2px 0 0;font-size:14px;font-weight:700;background-color:#f8f8f8}.item_body>.nav,.item_header{display:-webkit-box;display:-ms-flexbox;display:flex;-webkit-box-pack:center;-ms-flex-pack:center;justify-content:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center}.item_body>.nav{height:90px;padding:0 15px;text-align:center;color:#666;font-size:12px;line-height:20px}.nav_button{display:-webkit-box;display:-ms-flexbox;display:flex;-webkit-box-pack:center;-ms-flex-pack:center;justify-content:center}.difficult{border:none!important}