Semantic UI is a modern framework used in developing seamless designs for web pages, It gives the user a lightweight experience with its components. It uses predefined CSS and jQuery to incorporate different frameworks. It makes web pages look amazing and responsive.

Semantic UI Popup is used to display additional information through popups to the user. It alerts and provides the user with necessary information. Popups can help to save space and only show information when the user interacts with the webpage.

Semantic UI Popup fluid variation enables the popup to take the entire area of the offset container. The data itself gets adapted to the space available and space accordingly.

Semantic UI Popup Fluid Variation classes: 

• fluid: This class is used to add the popup element and it will take up its container width.

Syntax: Add the fluid class to the popup as follows:

<div class="ui fluid popup">
    ...
</div>

Example: In the following example, we have a popup element with some data that will fit itself inside the fluid popup.

Output:

Reference link: https://semantic-ui.com/modules/popup.html#fluid