A Style is set at document level and will apply the settings to every version in a document. Different styles or document settings cannot be applied to individual versions.
When you create a new style there are several tabs that can be selected to set various settings.

Details - Setting the name and status of the style
Document Size - Manage how your document will be sized
Document View - Manage how the pages of your document are presented
Toolbar - Configure the functionality and appearance of the toolbar
Pop-ups - Choose the settings for how interactivity pop-ups will appear
Background - Choose the settings for the background behind the document
Chart Settings - Configure the appearance of chart interactivity
Page Turn - Manage the settings for the page turn automation
Used By - Enables you to view which documents are using the style
Below is a breakdown of Document Size.
Manage how your document will be sized relative to the browser window.

Stretch to fit (for double page spread document)
The document will automatically scale to be as large as possible depending on the width and height of the browser window. If this option is deselected, the document will be displayed at a fixed size.Fixed Width/Stretch to Width/Stretch to Width and Height
Specify how single-page documents should be sized, by default these will be fixed width. There is also the option to select stretch to width (the document fill the width of the window but may scroll vertically), fixed width and height, or stretch to width and height (the document size will adjust based on the size of the window).
Helpful links
Other articles in the ‘Styles’ series
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