* Fix SVG being black
Adobe Illustrator SVGs have rendering problems on PTIO for unknown to
me reasons. Inkscape works fine.
* Rewrite with plain Flexbox
Nicer end-user experience than with crappy Bootstrap grid
JavaScript was checking if element clicked is exactly .nav-summary,
which isn't a problem when just clicking text inside it, but if we try
to click another element inside like <span>, it won't work, since now
this span is clicked, not .nav-summary.
Closes#1549
Dawid Potocki
