The font CSS property is either a shorthand property for setting font-style, font-variant, font-weight, font-size, line-height and font-family, or a way to set the element's font to a system font, using specific keywords.

font.css

/* font-size font-family */
font: 1em "Open Sans", sans-serif;

/* font-style font-size font-family */
font: italic 2em "Open Sans", sans-serif;

/* font-style font-variant font-weight font-size/line-height font-family */
font: italic small-caps bolder 16px/3 cursive;

/* font-style font-variant font-weight font-stretch font-size/line-height font-family */
font: italic small-caps bolder condensed 16px/3 cursive;

/* font-style font-variant font-weight font-size/line-height font-family|caption|icon|menu|message-box|small-caption|status-bar|initial|inherit */
font: italic small-caps 300 1em/1.5 Helvetica, Arial, "文泉驛正黑", "WenQuanYi Zen Hei", "儷黑 Pro", "LiHei Pro", "黑體-繁", "Heiti TC", "微軟正黑體", "Microsoft JhengHei", sans-serif;

/* The font used in system dialogs */
font: message-box;
font: icon;

/* Global values */
font: inherit;
font: initial;
font: unset;