Containers allow you to organize the layout of your content easier. Within the container you can add any kind of content, such as video, images, text, and even other containers. Containers have a lot of formatting options, such as applying different backgrounds, borders, and text color. Containers can be used in different ways depending on the layout mode of the chapter. 

Fixed layout containers

When a chapter is in fixed layout mode, the only way to add text to the page is using a container. A container will act as a content box, where text can be entered and wrap inside.

Reflowable layout containers

In reflowable layout, containers helpful with the layout of content. Instead of having all the content linear in a dull fashion, you can group some content together with their own formatting. External content can also wrap around the container. 

To add a container

Click on the Container tool. Fill in the properties you need and click Create.

Available properties

Container Type
How the container will resize on the screen. The container can have be set to "Expand vertically" making it expand depending on the amount of content inside. Setting to "Use a scrollbar" will allow you to set a fixed height. If content exceeds the height, a scrollbar will appear. Note that when exporting mobile apps, the container type will be forced to be "Expand vertically" for technical difficulties with nested scrolling.
The width of the container, with the choice of being pixel-based or percentage-based.
The height of the container element (pixel-based only). This is available only if the container type is "Use a scrollbar".
Align the container to either side and allow text to wrap beside it. Setting to 'None' centers the video element and consumes the entire horizontal space.
Disable text-wrapping for small screens The element will occupy the entire horizontal row if the ebook is displayed on a screen with small dimensions
Set an empty spacing around the container. Particularly useful when wrapping text around the element.
Set an empty spacing inside the container around the content. This spacing will be included with the background, and other formatting properties.
Class Mark this element with a CSS class
The default text color to be used inside the container. This can be overriden by setting the color for the text individually.
Background Color
The container's background color.
Background Image
An image that be used as a background for the container. The image will cover the entire area, with possible parts cropped out.
Border Color
The color of the container's border.
Border Thickness
The thickness of the border. Setting to zero will remove the border entirely.
Border Radius
The curvature of the container's borders (corner radius). If you would like no curved corners, set this value to zero.