Remove the left and right margin of an image

Hi,
on my site
https://www.cranio-karin.at/
there is a clickable image with different sections: “Cranio-Karin”, “Babys”, “Kinder” and so on…
I want to remove the left and right margin, so that the image is all over from left to the right (like the menu above).
what can I do?
Thank you!

this is the code:

<map name=”my-image-map”>

<area alt=”Startseite” coords=”0,0,599,105″ title=”Startseite” href=”http://www.cranio-karin.at/&#8221; shape=”rect”>
<area alt=”BABY Cranio-Sacral” coords=”0,106,119,576″ title=”BABY Cranio-Sacral” href=”https://www.cranio-karin.at/baby-cranio-sacral-behandlung/&#8221; shape=”rect”>
<area alt=”KINDER Cranio-Sacral” coords=”120,106,239,576″ title=”KINDER Cranio-Sacral” href=”https://www.cranio-karin.at/kinder-cranio-sacral-behandlung/&#8221; shape=”rect”>
</map>