How to make a popup responsive (fancybox)?

Question

css

How to make the image maintain proportions on small screens?
fantasybox.

Answer 1

Fancybox Options
fancyapps.com/fancybox/#docs

autoSize	If true, then sets both autoHeight and autoWidth to true	
Boolean; Default value: true
autoHeight	If set to true, for 'inline', 'ajax' and 'html' type content width is auto determined. If no dimensions set this may give unexpected results	
Boolean; Default value: false
autoWidth	If set to true, for 'inline', 'ajax' and 'html' type content height is auto determined. If no dimensions set this may give unexpected results	
Boolean; Default value: false
autoResize	If set to true, the content will be resized after window resize event	
Boolean; Default value: !isTouch

Answer 2

width: 100%
height: auto;

Answer 3

Спасибо! Почти помогло.. Как это поправить? :)