Bulma style overrides aren't working; Using Laravel 7.25.0 - laravel

Question

I've been using Bulma as a CSS framework for a site I'm building using Laravel, and for some reason, none of the overrides I've been writing have actually been taking place. In fact, if I remove everything from my app.scss file (including the line to import Bulma), nothing changes. I tried following the docs given for node-sass, and when i try to execute the npm css-build command, I get the following error:
> # css-build /Users/userName/Sites/siteName
> node-sass --omit-source-map-url sass/app.scss css/app.css
An output directory must be specified when compiling a directory
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! # css-build: `node-sass --omit-source-map-url sass/app.scss css/app.css`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the # css-build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
I know this is probably a terribly worded question, but I'd appreciate if anyone could point me in the right direction. I'm just genuinely lost.
app.scss:
#charset "utf-8";
#import url("https://fonts.googleapis.com/icon?family=Material+Icons");
// Variables
#import "_variables";
// Font Awesome
#import "font-awesome/scss/font-awesome";
// Bulma
#import "bulma/bulma";
// Bulma Vue Modules
#import "buefy/src/scss/buefy";
// Other SCSS Files
#import "overrides";
#import "helpers";
#import "manage";
#import "styles";
scripts portion of package.json:
"scripts": {
"dev": "npm run development",
"development": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
"watch": "npm run development -- --watch",
"watch-poll": "npm run watch -- --watch-poll",
"hot": "cross-env NODE_ENV=development node_modules/webpack-dev-server/bin/webpack-dev-server.js --inline --hot --disable-host-check --config=node_modules/laravel-mix/setup/webpack.config.js",
"prod": "npm run production",
"production": "cross-env NODE_ENV=production node_modules/webpack/bin/webpack.js --no-progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
"css-build": "node-sass --omit-source-map-url sass/app.scss css/app.css",
"css-watch": "npm run css-build -- --watch",
"start": "npm run css-watch"
},