borderimageoutset

border-image-outset is a CSS property used in web design to define the amount of space or extension beyond the border of an element where the border image is rendered. It controls how far the border image extends outside the element’s border box, effectively adding a visual margin around the element’s border area.

The border-image-outset property accepts one or more length values (such as pixels, ems, or percentages), which specify the distance(s) the image should extend beyond the border. When a single value is provided, it applies uniformly around all sides of the element. Multiple values can be used to specify different extensions for each side (top, right, bottom, left).

This property is particularly useful for creating effects where the border image needs to overflow or appear to protrude beyond the element’s boundary, enhancing visual emphasis or stylistic design. It complements other border image properties like border-image-source, border-image-slice, border-image-width, and border-image-repeat, which together control the appearance and behavior of border images.

If border-image-outset is set to zero, the image does not extend beyond the border box. Positive values will cause the image to extend outward, while negative values are not valid and will be ignored by browsers.

Supported in modern browsers, border-image-outset allows web designers to achieve more dynamic and creative border effects. Proper use of this property can enhance visual hierarchy and distinguish elements within a user interface.

Overall, border-image-outset provides designers with additional control over the spatial presentation of border images, aiding in the development of visually engaging web pages.