Register stylesheet and jquery from function.php

<?php


  function strict_scripts_styles() {


        /** --------------------------Javascript------------------------------- */

        /* Add main.js */
        wp_enqueue_script('popup', get_template_directory_uri() . '/assets/js/components/popup.js', array( 'jquery' ), '1.0', true);
        wp_enqueue_script('map', get_template_directory_uri() . '/assets/js/components/map.js', array( 'jquery' ), '1.0', true);
        wp_enqueue_script('nav', get_template_directory_uri() . '/assets/js/components/nav.js', array( 'jquery' ), '1.0', true);
        wp_enqueue_script('main', get_template_directory_uri() . '/assets/js/main.js', array( 'jquery' ), '1.0', true);

          /*------------------------------------- Stylesheet ---------------------------------------*/
        wp_register_style('arial', get_template_directory_uri() . '/assets/css/examples/fonts/arial.css', array(), '1.0.0');

        wp_enqueue_style('arial');

        /** --------------------------custom------------------------------- */

        /* Loads our main stylesheet. */
        wp_enqueue_style( 'strict-style', get_stylesheet_uri(), array( 'style' ));	
  }

add_action( 'wp_enqueue_scripts', 'strict_scripts_styles' );