.usage_part{background-color:#141414;padding:140px 0;color:#fff}.usage_part .usage_title{font-size:30px;line-height:1;font-family:HarmonyOS-L}.usage_part .usage_font{margin-top:30px;font-size:15px;line-height:29px}.usage_part .usage_box{margin-top:70px}.usage_part .usage_box .usage_select_item{width:210px;height:30px;margin-right:15px;position:relative}.usage_part .usage_box .usage_select_item .usage_select_head{position:relative;width:100%;height:100%;text-align:center;background-color:#fff;line-height:30px;color:#010101;font-size:13px;cursor:pointer}.usage_part .usage_box .usage_select_item .usage_select_head .iconfont{position:absolute;top:0;right:13px;color:#ff4d00;line-height:30px;font-size:13px;-webkit-transition:-webkit-transform .3s ease;transition:-webkit-transform .3s ease;transition:transform .3s ease;transition:transform .3s ease, -webkit-transform .3s ease}.usage_part .usage_box .usage_select_item .select_list_wrap{position:absolute;top:100%;left:0;width:100%;overflow:hidden;height:0;-webkit-transition:height .3s ease;transition:height .3s ease}.usage_part .usage_box .usage_select_item .select_list_wrap .select_list_box{max-height:180px;overflow:auto}.usage_part .usage_box .usage_select_item .select_list_wrap .select_list_box::-webkit-scrollbar{width:5px}.usage_part .usage_box .usage_select_item .select_list_wrap .select_list_box::-webkit-scrollbar-thumb{border-radius:6px;background-color:rgba(0,0,0,.5)}.usage_part .usage_box .usage_select_item .select_list_wrap .select_list_box::-webkit-scrollbar-track{border-radius:6px;background-color:hsla(0,0%,87.1%,.75)}.usage_part .usage_box .usage_select_item .select_list_wrap .select_list_box .select_list{background-color:#000}.usage_part .usage_box .usage_select_item .select_list_wrap .select_list_box .select_list .select_item{text-align:center;line-height:30px;font-size:13px;cursor:pointer;color:#fff;-webkit-transition:color .3s ease;transition:color .3s ease}.usage_part .usage_box .usage_select_item .select_list_wrap .select_list_box .select_list .select_item:hover{color:#ff4d00}.usage_part .usage_box .usage_select_item.default_item .usage_select_head{color:#b1b1b1}.usage_part .usage_box .usage_select_item.active .usage_select_head .iconfont{-webkit-transform:rotate(180deg);transform:rotate(180deg)}.usage_part .usage_box .usage_select_item.active .select_list_wrap{height:var(--h)}.usage_part .usage_box .usage_select_item:last-child{margin-right:0}