Style may be inlined using the STYLE attribute. The STYLE attribute may be applied to any BODY element (including BODY itself) except for BASEFONT, PARAM, and SCRIPT. The attribute takes as its value any number of CSS declarations, where each declaration is separated by a semicolon. An example follows:
red; font-family: 'New Century Schoolbook', serif
This paragraph is styled in red with the New Century Schoolbook font, if
Note that New Century Schoolbook is contained within single quotes in the STYLE attribute since double quotes are used to contain the style declarations.
Inlining style is far more inflexible than the other methods. To use inline style, one must declare a single style sheet language for the entire document using the Content-Style-Type HTTP header extension. With inlined CSS, an author must send text/css as the Content-Style-Type HTTP header or include the following tag in the HEAD:
Inlining style loses many of the advantages of style sheets by mixing content with presentation. As well, inlined styles implicitly apply to all media, since there is no mechanism for specifying the intended medium for an inlined style. This method should be used sparingly, such as when a style is to be applied on all media to a single occurrence of an element. If the style should be applied to a single element instance but only with certain media, use the ID attribute instead of the STYLE attribute.