- Increase the font size of the input field to make the text easier to
   read, and more importantly, stop iOS from zooming into the text field
   on mobile-optimized sites (ie. those with `<meta name="viewport"
   content="width=device-width, initial-scale=1">` in the host page)

 - Make the toolbar buttons bigger when using touch input and add space
   below the toolbar so that the browser can differentiate taps on the
   buttons from taps on text selection handles

 - Prevent toolbar overflowing annotation card on small screens.
   We use either horizontal scrolling or wrapping depending on the input mode
   (touch/non-touch). Scrolling saves vertical space, but could be inconvenient
   to use with a mouse or touchpad.

fixup! - Update comments