nl_tokens: inspired by https : // github . com / jkroso / viewport
pl_tokens: function updateViewport ( ) { const viewport = { } ; viewport . top = window . scrollY ; viewport . left = window . scrollX ; viewport . width = <mask> . innerWidth ; viewport . height = window . innerHeight ; viewport . right = viewport . left + viewport . width ; viewport . bottom = viewport . top + viewport . height ; debug ( 'viewport: %o' , viewport ) ; return viewport ; }