Moving Child menu to the left

I have installed menu block locally and am working through the CSS to how I would like it.
What I am getting stuck on is how when a link is expanded and shows the child link I would like the child links to start at the left hand side and not directly under the parent and also to close the gap between the current and next link on the parent menu. Image attached to show what I mean.
Hope someone can point me in the right direction. Thanks.