Line height for small use

Want to center the elements in the navigation bar up and down line-height（ Row height ） control .

for example ：
The following div in , If the line height of the text is 0, The effect is this ：

Change the row height to 54px after , The effect is this ：

It can be seen that , Row height line-height It can be easily controlled div The height of Chinese characters .
To prevent a small partner from getting the definition of row height wrong , A picture is posted below to illustrate ↓↓↓