The three things of line height and height: line height> height text lower; line height <height text upper

First understand the principle of row height. Row height includes the height of the content area, the upper half-line spacing and the off-duty line spacing. If line-heigt: 300px; font-size: 20px; calculates the spacing of 280px, the upper and lower half line spacing is 140px.

Line height> height text down;

height: 200px;
line-height: 300px;

Line height <height text up;

height: 200px;
line-height: 100px;