increase size of account login icon

the data-av_icon is on the following span tag:

#top a.cart_dropdown_link {
  right: 15px;
}

#top a.cart_dropdown_link span[data-av_icon] {
  font-size: 28px;
  color: var(--enfold-header-color-color);
}

/* === to influence the counter === */
#top a.cart_dropdown_link span.av-cart-counter {
  height: 20px;
  left: 64%;
  font-size: 18px;
  line-height: 20px;
  border-radius: 50%;
  background: var(--enfold-header-color-primary);
  color: var(--enfold-header-color-constant-font);
  margin: -22px 0 0 2px;
  padding: 2px 6px;
}

i inserted above the default colors – change them to your needs

yes – and your mentioned code above : a.cart_dropdown_link leads me to the wrong direction.
But better is to post the link to that page – so i can inspect it there. – is it the priver page?
(f.e. the demo page Enfold Shop does not have that account login icon inside main nav. it is on header_top.)

#top #header .av-main-nav  #menu-item-wc-account-icon > a {
  color: #f19809;
  font-size: 28px;
}

or if you like to have a hover effect on this:

#top #header .av-main-nav  #menu-item-wc-account-icon > a {
  color: #f19809;
  font-size: 28px;
  transition: color 0.7s ease;
}

#top #header .av-main-nav  #menu-item-wc-account-icon > a:hover {
  color: #1c60c7;
}