css and bootstrap classes not loading in vue template Laravel

only the css styles attached to body is loading in my vue template

body {
    font-family: 'Lato';
    font-style: normal;
    font-weight: 900;
    color:#003300;
  }

my bootstrap.js

window._ = require('lodash');

/**
 * We'll load the axios HTTP library which allows us to easily issue requests
 * to our Laravel back-end. This library automatically handles sending the
 * CSRF token as a header based on the value of the "XSRF" token cookie.
 */
//  try {
    // window.Popper = require('').default;
    window.$ = window.jQuery = require('jquery');

    require('bootstrap');