Test

Example(s):

The richer selector syntax of CSS2 may be used to create language-sensitive typography. For example, some Chinese and Japanese characters are unified to have the same Unicode codepoint, although the abstract glyphs are not the same in the two languages.

*:lang(ja-jp) { font: 900 14pt/16pt "Heisei Mincho W9", serif }
*:lang(zh-tw) { font: 800 14pt/16.5pt "Li Sung", serif }

This selects any element that has the given language - Japanese or Traditional Chinese - and requests the appropriate font.

Example(s):

    P      { font-weight: normal }   
    H1     { font-weight: 700 }     
    BODY   { font-weight: 400 }
    STRONG { font-weight: bolder } 

examples:

Child elements inherit the computed value of the weight.

font-stretch selects a normal, condensed, or extended face from a font family.

The relative keywords wider & narrower set the value to the next value.
Absolute keyword values have the following ordering, from narrowest to widest and function as shown:
ultra-condensed, extra-condensed, condensed, semi-condensed,
normal, semi-expanded, expanded, extra-expanded, ultra-expanded, -->

15.2.4 font-size and font-size-adjust

Initial: medium ; Applies to: all elements ; Inherited; Percentages: refer to parent element's font size ;

font-size describes the size of the font when set solid.

<absolute-size> refers to an entry in a table of font sizes computed and kept by the user agent:
xx-small | x-small | small | medium | large | x-large | xx-large

[ larger | smaller ]

For example, if the parent element has a font size of medium, a value of larger will make the font size of the current element be large. If the parent element's size is not close to a table entry, the user agent interpolates between table entries or round off to the closest one. The user agent may have to extrapolate table values if the numerical value goes beyond the keywords.

<percentage> A percentage value specifies an absolute font size relative to the parent element's font size. Use of percentage values, or values in ems leads to more robust and cascadable style sheets.

The actual value of this property may differ from the computed value due a numerical value on font-size-adjust and the unavailability of certain font sizes.

Child elements inherit the computed font-size value otherwise, the effect of font-size-adjust would compound.
editor's note:following examples are written with second string prefixed with <span style=font-size:xxxx; (opera and safari did em only with ; . opera and firefox didn't like a space before the pt form) with no other elements(no div or samp or blockquote) and no don't seem to be honored by all browsers!

For example, the popular font Verdana has an aspect value of 0.58; when Verdana's font size 100 units, its x-height is 58 units.
For comparison, Times New Roman has an aspect value of 0.46.
Verdana tends to remain legible at smaller sizes than Times New Roman.
Conversely, Verdana will often look too big if substituted for Times New Roman at a chosen size.

This property allows authors to specify an aspect value for an element that will preserve the x-height of the first choice font in the substitute font.
Values have the following meanings: none Do not preserve the font's x-height. <number> Specifies the aspect value. The number refers to the aspect value of the first choice font. The scaling factor for available fonts is computed according to the following formula:

  y(a/a') = c

where:

y = 'font-size' of first-choice font
a' = aspect value of available font
c = 'font-size' to apply to available font

Font size adjustments take place when computing the actual value of font-size. Since inheritance is based on the computed value, child elements will inherit unadjusted values.

This image shows several typefaces rasterized at a common font size (11pt. at 72 ppi), together with their aspect values. Note that faces with higher aspect values appear larger than those with lower. Faces with very low aspect values are illegible at the size shown.

This image shows the results of font-size-adjust where Verdana has been taken as the"first choice", together with the scaling factor applied. As adjusted, the apparent sizes are nearly linear across faces, though the actual (em) sizes vary by more than 100%. Note that font-size-adjust tends to stabilize the horizontal metrics of lines, as well.

15.2.5 Shorthand font tag

This tag applies to all elements and is inherited ;
Percentages  are allowed on font-size and line-height;

1. P { font: 12pt/14pt sans-serif }
2. P { font: 80% sans-serif }
3. P { font: x-large/110% "new century schoolbook", serif }
4. P { font: bold italic large Palatino, serif }
5. P { font: normal small-caps 120%/120% fantasy }
6. P { font: oblique 12pt "Helvetica Nue", serif; font-stretch: condensed }

In the second rule, the size percentage (80%) refers to the size of the parent element.
In the third rule, the line height percentage (110%) refers to the size of the element itself.

The first three rules do not specify the font-variant and font-weight and are set to initial values (normal).
The font family name "new century schoolbook", which contains spaces, is enclosed in quotes.

The fourth rule sets the font-weight to 'bold', the font-style to 'italic', and implicitly sets font-variant to 'normal'.

The fifth rule sets the font-variant ('small-caps'), font-size (120% of the parent's size), line-height (120% of the font size) and font-family ('fantasy'). The keyword 'normal' applies to the two remaining properties: font-style and font-weight.

The sixth rule sets the font-style, font-size, and font-family, the other font properties are set to their initial values.
Finaly sets font-stretch to condensed .

The values for system fonts:

System fonts may only be set as a whole; that is, font-family, size, weight, style, etc. are set at the same time but may then be altered individually.
System fonts can only be specified with this property, not with font-family, so font Individual properties such as font-weight are given values from the system font, which can be independently varied.

BUTTON { font: 300 italic 1.3em/1.7em "FB Armada", sans-serif }
BUTTON P { font: menu }
BUTTON P EM { font-weight: bolder }

BUTTON P {
  font-style: normal;
  font-variant: normal;
  font-weight: 600;
  font-size: 9pt;
  line-height: normal;
  font-family: Charcoal
} 

15.2.6 Generic font families

The five generic font families do not map to distinct fonts, they vary from browser to browser and may be specied by the browser user with a configuration or preferences option.
serif, sans-serif, cursive, fantasy and monospace

serif

Examples

sans-serif

Examples

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. Fonts for some scripts are almost always cursive.The term 'cursive' applies to a font for any script, although other names such as Chancery, Brush, Swing and Script are also used in font names.

Examples of fonts that fit this description include:

fantasy

Fantasy fonts, are primarily decorative while still containing representations of characters (as opposed to Pi or Picture fonts, which do not represent characters). Examples include:

monospace

The sole criterion of a monospace font is that all glyphs have the same fixed width. the effect is similar to a manual typewriter, and is often used to set samples of computer code.

Examples of fonts which fit this description include:

Many available fonts at www.google.com/fonts

A open source font for coding including design discussion source code pro. downloadfont squirrel

next: 15.3 Font Selection