CSS Column-Rule Customize Multi-Column Layouts

Introduction

The column-rule property in CSS is a shorthand for setting the width, style, and color of the line drawn between columns in a multi-column layout. This property helps you add visual separation between columns, improving the overall look and readability of your content.

Specification

The column-rule property is part of the CSS Multi-column Layout Module Level 1 specification. This specification ensures consistency and interoperability across different web browsers, making it easier to create robust and visually appealing multi-column layouts.

Syntax

The column-rule property can be defined using a simple syntax:

column-rule: column-rule-width column-rule-style column-rule-color;

Here’s a breakdown:

• column-rule-width: Specifies the width of the dividing line (e.g., px, em or keywords like thin, medium, thick).
• column-rule-style: Defines the style of the line (e.g., solid, dotted, dashed).
• column-rule-color: Sets the color of the line (e.g., blue, #0000FF).

You can also use global values like inherit, initial, revert, revert-layer, and unset.

Values

The column-rule property accepts values for width, style, and color:

• <'column-rule-width'>: Length value (e.g., px, em) or keywords (thin, medium, thick).
• <'column-rule-style'>: Styles like none, hidden, dotted, dashed, solid, double, groove, ridge, inset, outset.
• <'column-rule-color'>: Any valid CSS color value.

Examples of Usage

Basic Usage

HTML:

<p class="content-box">
  This is a bunch of text split into three columns.
</p>

CSS:

.content-box {
  padding: 0.3em;
  background: #ff7;
  column-count: 3;
  column-rule: dotted 2px #33f;
}

Customizing Width, Style, and Color

CSS:

.content-box {
  padding: 0.3em;
  background: #ff7;
  column-count: 3;
  column-rule: solid 5px red;
}

Using Different Styles

CSS:

.content-box {
  padding: 0.3em;
  background: #ff7;
  column-count: 3;
  column-rule: dashed 3px green;
}

Combining Constituent Properties

CSS:

.content-box {
  padding: 0.3em;
  background: #ff7;
  column-count: 3;
  column-rule-width: 2px;
  column-rule-style: dotted;
  column-rule-color: #33f;
}

Constituent Properties

The column-rule property is a shorthand for:

• column-rule-width: Sets the width of the line.
• column-rule-style: Defines the style of the line.
• column-rule-color: Sets the color of the line.

Browser Compatibility

The column-rule property is well-supported across modern web browsers:

• Google Chrome: Supported since version 50.0.
• Mozilla Firefox: Supported since version 52.0.
• Internet Explorer: Supported since version 10.0.
• Microsoft Edge: Supported since the initial release.
• Opera: Supported since version 37.0.
• Safari: Supported since version 9.0.

Browser Compatibility Table

Browser-Specific Prefixes

In some older versions of browsers, you might need to use vendor-specific prefixes:

-webkit-column-rule: solid 5px red;
-moz-column-rule: solid 5px red;
column-rule: solid 5px red;

Testing for Compatibility

It’s important to test your web designs in different browsers to ensure consistency. Tools like BrowserStack or cross-browser testing extensions can help you check that your multi-column layouts and the column-rule property work correctly everywhere.

Ensuring Graceful Degradation

For older browsers that don’t support the column-rule property, you can use fallback styles or progressive enhancement techniques. This ensures that the layout stays functional and looks good, even if it’s simpler.

See Also

For more on CSS properties related to multi-column layouts, check out these resources:

• Multiple-column Layout: This guide covers how to create and style multi-column layouts using CSS.
• column-rule-style: Learn about the column-rule-style property, which sets the style of the line between columns.
• column-rule-width: Discover how to adjust the width of the line between columns using the column-rule-width property.
• column-rule-color: Explore the column-rule-color property, which sets the color of the line between columns.
• CSS Border Properties: Understand the various CSS border properties for styling other elements on your webpage.
• CSS Multi-column Layout Module Level 1: Dive into the official specification for multi-column layouts, including detailed info about the column-rule property and related properties.