As seen here: https://stevegrunwell.com/blog/quick-tip-is_login_page-function-for-wordpress/

Add this function:

if ( ! function_exists( 'is_login_page' ) ) {
 function is_login_page() {
 return in_array( $GLOBALS['pagenow'], array( 'wp-login.php', 'wp-register.php' ) );
 }
 }

Then you can use:

if ( ! is_admin() && ! is_login_page() ) {
 wp_enqueue_style( 'base' );
 wp_enqueue_script( 'main' );
 }