All-in-one custom border spec
border-image

This property sets all of these properties in a single declaration: border-image-source, border-image-slice, border-image-width, border-image-outset, and border-image-repeat.
Property values
Some or all of the individual border image property values may be specified, in any order. See the separate specifications for each.
Examples
/* a custom border using a linear gradient */
border-image: linear-gradient(green, violet) 27;