CSS Reference Guide: outline

The CSS outline shorthand property is designed to draw a line around the outside of an element, distinct from the border property as it does not form part of the box model and cannot be limited to specific sides. This feature is particularly useful for emphasizing elements such as links when used with the a:focus selector. The outline property comprises three components: outline-color, outline-style, and outline-width, which can be specified together or individually with default values resolving when not defined. Colors can be set using various formats like keywords, hex values, or RGB/HSL notations, while styles range from solid to dotted or dashed lines, and the width can vary from thin to thick. Additionally, tools like LogRocket offer solutions for monitoring and analyzing frontend performance by capturing detailed user session data and providing insights into resource usage and user interactions.