fix firefox page padding [fixes #833]

[carlfairclough]

This provides a fallback for browsers which do not read min() max() css funtions.

Description

A stylus function has been created which will allow for linear scaling between two values.

34px @ 320px viewport → 72px @ 768px viewport
cssGrad(320, 34, 768, 72)

This function must be followed by a media query at the upper and lower limits, to prevent runaway scaling:

.el
  width cssGrad(320, 34, 768, 72)
  @media screen and (min-width: 768px)
    width: 72px

A fixed-px fallback has been added for the list blank states, as that was previously using min().

Related Issue

#833

[samajammin]

@carlfairclough I'm still seeing this issue of Firefox,

1. When I make my browser slightly smaller (but still have sidebar)

2. When the browser window is small enough that the sidebar disappears (e.g. on iPad):

Please make the needed updates & confirm these are addressed.

[carlfairclough]

@samajammin This doesn't happen when in dev so I'm assuming it's a part of the stylus build process, perhaps ensuring that there is only one of each property per class?

I've admitted defeat — this is using media queries now