18. Map
{ background-color: #4a7370; }
#countries {
::outline {
line-color: #85c5d3;
line-width: 2;
line-join: round;
}
polygon-fill: #fff;
}
This stuff is called
CartoCSS , and it
looks like web CSS
19. Grab some open data and get started
D.C. Census Tracts:
http://db.tt/wNnjCNzK