Png Margin or Border Issue

me and my friends are trying to make a “risk!” tipe of game with a world map and everything on a html page (css js and jq included), we wanted to separate each of the “countries” by using polygons but we found that really long to do and pretty hard, so we thought of using png without background images to do the sections and the borders, problem is, even if an image has no background it still has a “margin” or a trasparent background that makes the “hitbox” of the country way bigger than it should be.
i searched all over the internet but couldnt find nothing

we tried to put the images toghether but ofc it didnt work out.