How do I make my logo appear half on and half below my header?

we had to see the site.
on most cases (it is only to set the logo to overflow:visible and set the image size f.e.

.logo, #top .logo a {
    overflow: visible;
}

.logo img {
    height: 150% !important;
    max-height: 96px !important;   /*** Values depending on your header dimensions ***/
}

If you have a svg instead (inline svg) there had to be additional adjustment to make

well you had to wait til mods are here – i’m participant as you
on your site (not Enfold) this code above allready works too -but on enfold the overflow option is necessary.

without a link to the live page – it’s hard to give concrete advice.
see comment above: i’m participant as you
if you are not willing to make the link public – then you have to wait for mods help.

the 150% belongs to the surrounding container. So if header-height was first set to 100px then 150% is a max-height of: 150px.
on his own website there is a header-height of 64px – so 150% are 96px.

the overflow: visible end up in a logo that is bigger than its surrounding container and is visible over it.
So thats my comment – it depends on header-height.

So for shrinking headers the height in relative Values is important. The max-height is the starting point.

https://webers-testseite.de/cynthia/unite4-2/
my header there is set to 160px
because i want to start with a logo img height of 350px. the The height must be set to: 350:160 = 219%