My requirement goes something like follows:
Say I am building an angular js app for, say, a samsung galaxy tab p3100.
When you hold the tablet vertically with the short-side facing upwards you want one simple view, say, a login form.
When you hold the tablet with the long-side up, the screen rotates. In this orientation, there is more real estate, hence, the login form occupies the first 4 columns and the rest 8 columns will host some other content - advertisements, etc. (Bootstrap vocabulary - dividing the screen to a 12 column layout).
Content should be dynamic as per device orientation.
What is a good library or framework that has an easy way to write such apps?