Auto height on parent container with Absolute/Fixed Children

Question

Im trying to set an automatic height a div that contains 2 child elements, positioned fixed and absolutely respecitvely.

I want my parent container to have an auto h

Answer 1

A little late to the party, but this may help someone as this is how I resolved the issue recently without JS - IF the children maintain their aspect ratio as they shrink for mobile devices. My example relates to making a jQuery.cycle slideshow responsive, for context. Unsure if this is what you're trying to achieve above, but it involved absolutely positioned children within a container which has 100% page width on mobile and explicit dimensions on larger screens.

You can set the parent's height to use viewport width units (vw), so the height adapts relative to the device's width. Support is broad enough these days that most mobile devices will use these units correctly, bugs and partial support don't relate to vw (but rather, to vmin and vmax in IE). Only Opera Mini is in the dark.

Without knowing what the children are doing between responsive points in this example (the jsfiddle has explicit heights set), let's assume the height of the children scales down predictably relative to the device width, which allows you to fairly accurately assume the height based on aspect ratio.

.container{ height: 75vw; }

http://caniuse.com/#feat=viewport-units

Do note known issue #7 on caniuse if you're going for 100vw as a width measure, but here we're playing with height!