One can assume that replaced elements come with their own intrinsic dimensions. If the value of the 'width' property is 'auto', the intrinsic width is used as the width of the element. The 'height' property is used in the same manner. Replaced elements can be either block-level or inline. The height of lines All elements have a 'line-height' property that, in principle, gives the total height of a line of text.
Space is added above and below the text of the line to arrive at that line height.
For example, if the text is 12pt high and 'line-height' is set to '14pt', an extra space of 2pt is added, namely 1pt above and 1pt below the line. Empty elements influence these calculations just like elements with content. The difference between the font size and the 'line-height' is called the leading . Half the leading is called the half-leading . After formatting, each line will form a rectangular line-box .