Unitless line-height value in CSS

The value of the line-height property does not necessarily have to be a number in some units. You can also just write a number or a fraction. In this case, the actual value of line-height can be found by multiplying it by the value of font-size.

For example, font-size is 10px, and line-height is 1.5. In this case, the actual value of line-height will be 10px * 1.5 = 15px. Well, the visible white space between the lines of text will be 5px: 15px - 10px = 5px.

The advantage of this method of setting line-height is that when you change the font size, the line spacing will automatically change.

Let's look at the application of what is described using an example:

<p>
	long text...
</p>

p {
	font-size: 20px;
	line-height: 1.5;
	text-align: justify;
	width: 400px;
}

Let the font size for paragraphs be 30px. Set the line-height property so that the visible white space between paragraphs is 15px. Use the unitless value line-height for this.