Header dropdown

I'm trying to make my header-nav-folder-content to expand over the whole page on desktop (see example img. 2), but keep the position of the header-nav-folder-items to straight below the header-nav-folder-title (aligned to the left) - se example img. 1.
 

In addition I'm trying to force the header-nav-folder-content to 'start' below the header's solidHeaderBackgroundColor - rather than how it looks now..(see 'As it looks now' image)

Does anyone have a solution for this through custom CSS?

This is what I have so far in terms of my 'custom css':
/* Drop down menu styling */
.header .header-nav-wrapper a, .header .language-item a {
    text-decoration: none;
    backface-visibility: hidden;
    padding: 0.8em 0;
}
.header-nav .header-nav-item--folder .header-nav-folder-content {
  min-width: 100em;
}
:not(.header--menu-open) .header-nav-folder-content, :not(.header--menu-open) .language-picker-content {
    background-color: #dceff4;
  font-weight: thin !important; 
}
 

I just found this - he solved averything.. 😛