Wp nav menu added via function - styling with flexbox

flexbox-menu.css

/*	Objective: Center and style a wp nav menu added 
  	via function hook into a row using flexbox
	
  	I don't know how to code in my own classes into a function 
  	but wp was nice enough to add their own 
*/


/* 	Code in child theme's function.php  */

/*	adding nav menu to cpt brand_ambassadors singe post 

add_action( 'generate_after_header', function() {
    if ( is_singular( 'brand_ambassadors' ) ) {    	
        wp_nav_menu( array(
            'menu' => 'CPT Ambassador Menu', // Do not fall back to first non-empty menu.  Was Primary Menu
            'theme_location' => 'cpt-ambassador-menu',
            'fallback_cb' => '__return_false'             // Do not fall back to wp_page_menu()
        ) );
    }
} );

*/


/*	Html page markup code output 

<div class="menu-cpt_ambassador_nav-container">
	<ul id="menu-cpt_ambassador_nav" class="menu">
		<li id="menu-item-3222" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-3222"><a href="#social-title" data-ps2id-api="true" class="_mPS2id-h">Social</a>
		</li>
		<li id="menu-item-3221" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-3221"><a href="#book-class-title" data-ps2id-api="true" class="_mPS2id-h">Book Class</a></li>
		<li id="menu-item-3223" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-3223"><a href="#my-picks-title" data-ps2id-api="true" class="_mPS2id-h">My Picks</a></li>
		<li id="menu-item-3219" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-3219"><a href="#about-title" data-ps2id-api="true" class="_mPS2id-h">About</a></li>
		<li id="menu-item-3224" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-3224"><a href="#contact-title" data-ps2id-api="true" class="_mPS2id-h">Contact</a></li>
	</ul>
</div>

*/

/*	css I added and placed in the child theme via customizer
  	note: adding to style.css didn't work. New file not minimized?
  	wp-admin - appearance - customizer - add css 
	Thanks in advance for taking a look.
*/

.menu-cpt_ambassador_nav-container {	
	background-color: lime;
	color: red;
}

#menu-cpt_ambassador_nav ul {
	display: flex;
	justify-content: space-evenly;
	flex-flow: row wrap;
	margin-left: 0px;
}