Custom code to make header logo bigger doesn't work any more in 7.0 site

Add this code:
.Header-branding-logo {

max-width: 100%;
  width: 60vw !important;
}

Image look grainy to fix that you have to remove the sizes attribute from the image tag with javascript.

This is for mobile:
.Mobile-bar-branding-logo {
  width: 340px;
}