幽灵空白节点存在于行框盒子的前面（必要条件 ：需要h5的文档声明）（表现形式：没有宽度，永远透明，不能通过脚本获取）
因为有现成的提问和回答，所以将截图摘于此。
原文地址：https://segmentfault.com/q/1010000014296346/a-1020000014298050
提问：
回答：
最后，感谢两位前辈提供的精确回答。
附w3c规范：
Line boxes are created as needed to hold inline-level content within an inline formatting context. Line boxes that contain no text, no preserved white space, no inline elements with non-zero margins, padding, or borders, and no other in-flow content (such as images, inline blocks or inline tables), and do not end with a preserved newline must be treated as zero-height line boxes for the purposes of determining the positions of any elements inside of them, and must be treated as not existing for any other purpose.