#toplevel_page_porto .dashicons-porto-logo {
    background: url(images/porto_logo.png) no-repeat;
    background-position: 0 0;
}

#toplevel_page_porto:hover .dashicons-porto-logo {
    background-position: 0 -68px;
}

#toplevel_page_porto.wp-has-current-submenu .dashicons-porto-logo {
    background-position: 0 -34px;
}

#wp-admin-bar-porto .ab-item .ab-icon {
    width: 20px;
    height: 20px;
}
#wp-admin-bar-porto .ab-item .ab-icon:before {
	content: '';
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	background: url(images/porto_logo.png) -8px 0 no-repeat;
	transition: none;
}

#wp-admin-bar-porto:hover .ab-item .ab-icon:before {
    background-position: -8px -68px;
}