Social media icon sizes and page placement

here on that page you can achieve this by:
(the old way – because using font-icons)

#top .main_menu {
  right: 145px;    /* === A correction value for the now broader social_bookmarks === */
  padding-right: 10px;
}

#header_main .social_bookmarks {
  margin: 0;
  height: 40px;
  top: 50%;
  transform: translateY(-50%);
}

#top .social_bookmarks li {
  width: 36px;
}

#top .social_bookmarks li a {
  width: 40px;
  line-height: 40px;
  min-height: 40px;
}

#top .social_bookmarks li a:before {
  font-size: 24px
}

Perhaps it needs to be adapted for your website. As a participant, I cannot see any private content, so I’m afraid I can’t offer any better advice.

NEXT: now the bookmarks are svg icons – so the css had to be different.
But i do not find an example page to do so. I had to look on one of my installatons to have that different css.

#top .avia-menu.av_menu_icon_beside {
  border-right: none;
  padding-right: 10px;
  margin-right: 10px;
}

#top nav .social_bookmarks {
  position: relative;
  transform: translateY(-50%);
  margin: 0 !important;
  height: 40px !important;
}

#top .social_bookmarks li {
  width: 40px;
  margin-left: 3px
}

#top .social_bookmarks li a {
  width: 40px !important;
  line-height: 40px;
  border-radius: 10px !important;
  min-height: 40px;
}

#top .social_bookmarks li.avia-svg-icon img[is-svg-img="true"], 
#top .social_bookmarks li.avia-svg-icon svg:first-child {
  height: 1.5em;
  width: auto;
  margin-top: 5px;
}