Fixed audio card in What's New at narrow widths and header pop ups
Fixed audio card in What's New at narrow widths and header pop ups

- adjusted min and max widths of various elements in audio card in What's New only to stop it from visually breaking when at specific viewport widths
- quick fixes for z-index of certain elements across cards in What's New only so they didn't appear above the page header

TryGhost/Ghost,TryGhost/Ghost,TryGhost/Ghost