How to import css with webpack?

TWO PART QUESTION

My steps:

1. Created empty folder
2. opend cmd
3. navigate to folder and run npm init -f
4. run vue init webpack
5. run npm install
6. npm i bootstrap-vue
7. npm run dev

my main.js:

import Vue from 'vue'
import App from './App'
import router from './router'

import BootstrapVue from 'bootstrap-vue'
import 'bootstrap/dist/css/bootstrap.css'
import 'bootstrap-vue/dist/bootstrap-vue.css'

Vue.use(BootstrapVue);

Vue.config.productionTip = false

/* eslint-disable no-new */
new Vue({
    el: '#app',
    router,
    render: h => h(App)
})

webpack.base.conf.js:

var path = require('path')
var utils = require('./utils')
var config = require('../config')
var vueLoaderConfig = require('./vue-loader.conf')

function resolve(dir) {
    return path.join(__dirname, '..', dir)
}

module.exports = {
    entry: {
        app: './src/main.js'
    },
    output: {
        path: config.build.assetsRoot,
        filename: '[name].js',
        publicPath: process.env.NODE_ENV === 'production' ?
            config.build.assetsPublicPath : config.dev.assetsPublicPath
    },
    resolve: {
        extensions: ['.js', '.vue', '.json'],
        alias: {
            '@': resolve('src'),
        }
    },
    module: {
        rules: [{
                test: /\.vue$/,
                loader: 'vue-loader',
                options: vueLoaderConfig
            },
            {
                test: /\.js$/,
                loader: 'babel-loader',
                include: [resolve('src'), resolve('test')]
            },
            {
                test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
                loader: 'url-loader',
                options: {
                    limit: 10000,
                    name: utils.assetsPath('img/[name].[hash:7].[ext]')
                }
            },
            {
                test: /\.(mp4|webm|ogg|mp3|wav|flac|aac)(\?.*)?$/,
                loader: 'url-loader',
                options: {
                    limit: 10000,
                    name: utils.assetsPath('media/[name].[hash:7].[ext]')
                }
            },
            {
                test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
                loader: 'url-loader',
                options: {
                    limit: 10000,
                    name: utils.assetsPath('fonts/[name].[hash:7].[ext]')
                }
            },
            { //this rule will only be used for any vendors
                test: /\.css$/,
                loaders: ['style-loader', 'css-loader'],
                include: [/node_modules/]
            },
            {
                test: /\.css$/,
                loaders: ['to-string-loader', 'css-loader'],
                exclude: [/node_modules/] //add this line so we ignore css coming from node_modules
            },

            {
                test: /\.css$/,
                use: [
                    'style-loader',
                    'css-loader'
                ]
            }
        ]
    }
}

when I run this I get:

Module build failed: Unknown word (5:1)

Part 2:

After some time found a solution to the above problem by installing a loader package and changin my main.js to this:

import Vue from 'vue'
import App from './App'
import router from './router'


import '!style-loader!css-loader!bootstrap/dist/css/bootstrap.css';


/* eslint-disable no-new */
new Vue({
    el: '#app',
    router,
    render: h => h(App)
})

this solved my first problem BUT:

If i try to add a local css file like so:

import Vue from 'vue'
import App from './App'
import router from './router'


import '!style-loader!css-loader!bootstrap/dist/css/bootstrap.css';
import './content/bootstrapGrid.css'

/* eslint-disable no-new */
new Vue({
    el: '#app',
    router,
    render: h => h(App)
})

I again get the same error:

Module build failed: Unknown word (5:1)

I am new to webpack, vue and the entire SPA. Been at this for a while now and im stuck, anyone that can see what I am missing?