Diving into CSS Containment

Introduction to CSS Containment

CSS Containment is one of the advanced features of CSS that is designed to improve the rendering performance of specific parts of a web page. This feature allows developers to optimize the rendering performance of the page. By using CSS Containment, you can create specific contexts for browsers, size, and style adjustments concerning different elements on the page.

Assume you have a complex web page consisting of several large and intricate components. By implementing CSS Containment, you can tell the browser that a specific component and its variables only affect itself and will not impact the rest of the page.

The main goal of using this feature is to enhance the performance of web pages. Therefore, the browser can make changes only in specific regions and minimize unnecessary calculations and rendering process. This is particularly beneficial in complex pages that contain a lot of elements.

Many developers are still unfamiliar with this feature and may overlook its significance; however, considering the importance of fast loading and high performance web pages, the application of CSS Containment is growing.

In continuation, we will delve into the various features of CSS Containment and examples of its application.

Example Code for CSS Containment

  <style>
    .container {
      contain: layout paint style;
    }
  </style>

  <div class="container">
    <p>This content is contained!</p>
  </div>

Step-by-step Code Explanation

.container – This class is defined for the element that must have the containment property.
contain: layout paint style; – This syntax is used to ensure that no effects occur on the layout, painting, or rendering processes of elements outside this containment.
<div class="container"> – A containing div that possesses the containment property.
<p> – A paragraph that resides within the containing div and is typically rendered in the browser.