iOS gradient

On iOS, diagonal gradients don't look right when the container has a larger height than width:


I don't know the terms, but the "contour" lines that show the same color should be perpendicular to the direction of the gradient, as they are on Android:


Strangely, while the Android implementation is supported by [the MDN docs](https://developer.mozilla.org/en-US/docs/Web/CSS/linear-gradient#Composition_of_a_linear_gradient), OSX Google Chrome shows [this Codepen](https://codepen.io/anon/pen/ZxVdYX) the same way as the iOS implementaiton above.

This is a minor change for this roughly 4:3 height:width ratio, but for large stretched-out containers (like a long ScrollView - our use case), the difference becomes much more pronounced.