Answer:
Responsive design
Step-by-step explanation:
Responsive design -
It refers to the method o developing any web design, which is irrespective of the screen size, orientation and platform, is referred to as the responsive design.
In simple terms, the website can be accessed with proper efficiency in laptop , phones or any other platform.
The website is enabled with the combination of flexible grids and layout, by which the user can open the site in laptop as well as mobile phone, and the site can easily change the resolution, according to the platform.
Hence, from the given scenario of the question,
Katie designed a responsive design, which enables her site to sit to the cell phone as well.