Visual tweaks.

Some tweaks.

CSS:
   * Provide a consistent side margin on text elements when window width is below 640px.
   * More consistent alignment of text elements in general
   * Breathing room between lines.
   * Remove left-side padding from annotations text when window-width is below 640px.
   * Use flexbox to stick footer to the bottom of window.

Template:
   * Don’t display search form on print.
   * Break footer text.