.t_nav{ color: #313131; position:fixed;top:0;left:0; width:100%;z-index:9999; background-color: #fff  }
.tab{ font-size:24rpx; position: absolute; right: 24rpx; top:-30rpx }
.contant{ display: flex; justify-content: center; align-items: center; width: 100%; position: relative }