The border property is shorthand for setting an element's border-width, border-style, and border-color in one declaration, for example border: 2px solid #333. It draws a line around the element between its padding and margin.
Use the side-specific properties like border-top, border-right, border-bottom, or border-left, each accepting its own width, style, and color. In this tool, enable "Target individual border" to configure each edge separately.
A border needs a border-style value to render; width and color alone are not enough. The default style is none, so setting only border-width or border-color produces no visible border. Choose a style such as solid, dashed, or dotted.
These are 3D styles that use the border color to fake depth: groove looks carved in, ridge looks raised, inset makes the whole box look sunken, and outset makes it look embossed. The effect is subtle and depends on the border color and width.