columnseprule

Columnseprule is a term used to describe the visual separation between columns in a multi-column layout. In standard CSS, this effect is implemented using the column-rule property, which draws a vertical line between adjacent columns and controls its appearance.

The column-rule property is a shorthand that can specify the width, style, and color of the separator. It is typically used alongside other multi-column properties such as column-count or column-width to create layouts with multiple columns. Example: a rule like column-rule: 1px solid #333 creates a single-pixel solid line between columns. The appearance can also be controlled with the longhand properties column-rule-width, column-rule-style, and column-rule-color for finer adjustments. The gap between columns is set with column-gap, and the total layout is defined with column-count or column-width.

Compatibility and usage notes: column-rule is supported by modern browsers in standard CSS. It applies only in contexts where more than one column is present. If no separation is desired, column-rule can be set to none. Although some documentation or codebases may reference an informal or nonstandard spelling such as columnseprule, the official CSS property remains column-rule.

See also: column-count, column-width, column-gap, column-rule-width, column-rule-color.