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.
Style information can be contained in the HTML file itself or in an external file. In this tutorial we will use an internal stylesheet. 1  Click on the first radio button labeled âstyle applied to all elements of type.â. 2  Choose an element to create a style rule for from the menu at the bottom of the dialog.