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.
CSS Rule Sets. 1  SELECTOR refers to the targetted HTML element(s). 2  You can simply insert the actual name of the HTML element you wish to target (known as a type selector) or you can be more specific by using class or id selectors. 3  property refers to a CSS property.