div{font: italic 1.2em "Fira Sans", serif;
font: italic small-caps bold 16px/2 cursive;
font-family: serif;
font-size: 12px;
font-size: 80%;
font-stretch: condensed;
font-style: italic;
font-style: oblique 40deg;
font-weight: 400;// normal
font-weight: 700;// bold

The font property is shorthand for most useful font properties. Below formal syntax:

[[font-style|[normal|small-caps]|font-weight|font-stretch]?font-size[/line-height]? font-family]  
property description
font-family Specifies a prioritized list of one or more font family names and/or generic family names for the selected element.
font-size Sets the size of the font.
font-stretch Selects a normal, condensed, or expanded face from a font. Possible values are:
  • semi-condensed
  • condensed
  • extra-condensed
  • ultra-condensed
  • normal
  • semi-expanded
  • expanded
  • extra-expanded
  • ultra-expanded
  • x% - a percentage value between 50% and 200%
font-style Sets whether a font should be styled with a normal, italic, or oblique face from its font-family. Possible values are:
  • normal
  • italic
  • oblique
  • oblique xdeg
font-weight Sets the weight of the font. The weights available depend on the font-family that is currently set. Possible values are numbers from 100 to 900 or one of the values listed below:
  • normal
  • bold
  • lighter
  • bolder
line-height Sets the height of a line box. It's commonly used to set the distance between lines of text.

You can specify the value in given units or as a percentage relative to the font size of the element itself.

Value without unit will be multiplied by the element's own font size. In most cases, this is the preferred way to set line-height and avoid unexpected results due to inheritance.

generic family names

Generic family names are keywords and must not be quoted. A generic font family should be the last item in the list of font family names. Used when no other fonts are available.

name description
serif Glyphs have finishing strokes, flared or tapering ends, or have actual serifed endings, for example "Lucida Bright", "Palatino", "Palladio", "serif".
sans-serif Glyphs have stroke endings that are plain, for example "Arial", "Verdana", "Helvetica", "Trebuchet MS".
monospace All glyphs have the same fixed width, for example "DejaVu Sans Mono", "Courier New", "Lucida Console".
cursive Glyphs in cursive fonts generally have either joining strokes or other cursive characteristics beyond those of italic typefaces. The glyphs are partially or completely connected, and the result looks more like handwritten pen or brush writing than printed letterwork.
fantasy Fantasy fonts are primarily decorative fonts that contain playful representations of characters, for example "Papyrus".
system-ui Glyphs are taken from the default user interface font on a given platform.
ui-serif The default user interface serif font.
ui-sans-serif The default user interface sans-serif font.
ui-monospace The default user interface monospace font.
ui-rounded The default user interface font that has rounded features.
emoji Fonts that are specifically designed to render emoji.
math This is for the particular stylistic concerns of representing mathematics: superscript and subscript, brackets that cross several lines, nesting expressions, and double struck glyphs with distinct meanings.
fangsong A particular style of Chinese characters that are between serif-style Song and cursive-style Kai forms. This style is often used for government documents.