Will CSS conflict after iframe nesting?

The basic syntax of

<iframe> is as follows:

<iframe src="url"></iframe>

The src attribute specifies the URL of the webpage to be nested.

CSS Conflicts

In web development, we often set different styles for different elements to meet the design requirements of the page. However, when using <iframe> to nest other webpages, we may encounter CSS style conflicts. This is because the webpage inside the <iframe> has its own CSS styles, and the outer page also has its own CSS styles. When these two pages share the same selectors or attributes, a CSS conflict occurs.

Common CSS conflict issues include the following:

1. Style Override: When the inner and outer webpages use the same selector but set different styles, this can cause style overlap, resulting in unexpected display effects.

2. Style inheritance: When elements on an internal page don’t have specific styles set, they inherit the styles of the external page, resulting in confusing display effects.

3. Nesting level: When <iframe> is nested multiple times, the CSS styles at different levels may affect each other, causing page confusion.

How to Avoid CSS Conflicts

To avoid CSS conflicts, we can take the following approaches:

1. Use the sandbox attribute of <iframe>

The sandbox element provides a sandbox attribute that can restrict the behavior of the nested page, including JavaScript execution, form submission, and link redirection. By properly setting the sandbox attribute, you can avoid unnecessary CSS conflicts.

<iframe src="url" sandbox="allow-same-origin"></iframe>

2. Set styles for <iframe>

You can avoid CSS conflicts by setting styles for <iframe>, such as width, height, and borders. Also, consider setting separate styles for internal and external pages to ensure they don’t affect each other.

<iframe src="url" style="width: 100%; height: 300px; border: none;"></iframe> 

3. Use the seamless attribute of the iframe tag.

The <code>seamless attribute of the