Update main.css

Updated main.css, only part of stylesheet was there.
Update main.css

Changed <hr> background
Added HotCold Project
Changed script
Merge remote-tracking branch 'origin/master' into gh-pages
Merge remote-tracking branch 'origin/master' into gh-pages
Merge remote-tracking branch 'origin/master' into gh-pages
Edits to .js
edits html