css实现斜梯形图标，例如右上角置顶图标

.top{
		border-bottom: 28rpx solid #FFCA28;
	    border-left: 28rpx solid transparent;
	    border-right: 28rpx solid transparent;
	    height: 0rpx;
	    width: 100rpx;
		transform: rotate(45deg);
	}