The page you linked to is a Drupal page.
Drupal is a Content Management System whose pages are not designed to fit completely within a user's browser window.
Vertical scrolling is normal and (on most Drupal pages) necessary to view all content on the page.
It would not be possible to constrict all content on a Drupal page to fit within a user's browser window (no matter what its size) without any scrolling.

You would have to manually construct your web page using the View Resizable Gallery with Top Menu Example sample gallery as a template. You can view the source of the web page in a browser, copy it and swap the header, gallery and footer for your own content.

Alternatively, you could try just reducing the height of your gallery (in your Drupal page) so that less vertical scrolling is necessary for most users.

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