Main menu font size and color. Different search icon size

Ive trying to change size and color of main menu text and search icon. I would like it to have differrent sizes.

Search icon part doesnt works.

My code:

	/* main menu elements */
	.header_color .main_menu ul:first-child > li > a { font-size: 13px!important; font-weight: 500; color: #35b8b4!important; background-color: #fff!important; }
	.header_color .main_menu ul:first-child > li > a:hover { color: #000!important; }
	.header_color .main_menu ul:first-child > li.current-menu-item > a, .header_color .main_menu ul:first-child > li.current_page_item > a { color: #000!important; }

	/* main menu search icon */

	#top #menu-item-search.menu-item-search-dropdown>a {
	font-size: 26px;
	}

Second question is about search icon:
I would like to have this whole array $avia_config['font_icons'] = apply_filters('avf_default_icons', array( in functions.php of my child theme. My changes work in original file but when i copy it to functions.php in my child theme they dont work.