I am following an online tutorial which uses truffle webpack for designing the dapp. Inside, I have written some code for index.html and app.js which are stored in app and app/javascripts folders respectively. When I run the local server using 'npm run dev' and inspect the HTML page in chrome I get an error which says HTML cannot find the stylesheet declared. To further test I also observed that 'app.js' could not import web3 as well.
Please suggest how can I import the CSS file and related web3 directory in app.js. For reference, I have added screenshots of HTML error and my folder structure.