fix trail walk progress being slightly bigger than viewport
"breaking out" of containers like that is generally not a good practice. this sets `TrailWalk-progressSticky`'s width to 100%, removes that margin black magic and `TrailWalk`'s 800px width limit (other children that need one have their own anyway)
authored by
koi.rip
and committed by
tangled.org
d28aa0a9
86523d5c