Mega menu width and position

I want to make the mega menu with the width of container holding logo and the menu.

How it has to much margin from the right, I tried to move from the Mega menu settings on the style -> submenu style -> mega panel -> offset, using the pixel or the percent but it didn’t work.

it is the 3rd link from the right after the logo, you can set the right site of the mega menu is not under the logo, it is much to the right.

How do I align it to the right place?

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