Photo credit: Danika Bannasch, UC Davis. Hereditary equine regional dermal asthenia (HERDA) is a genetic skin disease found in the Quarter Horse. The disease is characterized by hyperextensible, elastic skin, severe dermatologic lesions, and often scarring along the back and withers of affected horses.
Contents. 1  Introduction to style sheets. 2  Adding style to HTML Setting the default style sheet language. 3  External style sheets Preferred and alternate style sheets.  Cascading style sheets Media-dependent 1  cascades. Hiding style data from user agents.  Linking to style sheets with HTTP headers.
A Simple Guide to HTML. CSS is short for Cascading Style Sheets, and is the preferred way for setting the look and feel of a website. The style sheets define the colour, size and position of text and other HTML tags, while the HTML files define the content and how it is organised.