CSS folder not appearing in sources with Gulp - css

Question

I'm building a React page and using Gulp. My styles compile correctly to CSS and get saved locally in my destination folder (./build/css) as they should. However, when I inspect the page in the browser, the CSS folder isn't in the build folder, and none of my styles are showing up. Here's my app structure:
| build
|- css
|- style.css
|- images
|- main.js
| css
|- style.styl
| resources
|- images
| scripts
|- components
|- App.js
|- etc...
|- main.js
| gulpfile.js
| index.html
| package.json
And here's my gulpfile:
/*
Styles Task
*/
gulp.task('styles',function() {
// Compiles CSS
gulp.src('css/style.styl')
.pipe(stylus())
.pipe(autoprefixer())
.pipe(gulp.dest('./build/css/'))
.pipe(reload({stream:true}))
});
/*
Images
*/
gulp.task('images',function(){
gulp.src('resources/images/**')
.pipe(cache(imagemin({ optimizationLevel: 5, progressive: true, interlaced: true })))
.pipe(gulp.dest('./build/images/'))
});
/*
Browser Sync
*/
gulp.task('browser-sync', function() {
browserSync({
// we need to disable clicks and forms for when we test multiple rooms
server : {},
middleware : [ historyApiFallback() ],
ghostMode: false
});
});
function handleErrors() {
var args = Array.prototype.slice.call(arguments);
notify.onError({
title: 'Compile Error',
message: '<%= error.message %>'
}).apply(this, args);
this.emit('end'); // Keep gulp from hanging on this task
}
function buildScript(file, watch) {
var props = {
entries: ['./scripts/' + file],
debug : true,
cache: {},
packageCache: {},
transform: [babelify.configure({stage : 0 })]
};
// watchify() if watch requested, otherwise run browserify() once
var bundler = watch ? watchify(browserify(props)) : browserify(props);
function rebundle() {
var stream = bundler.bundle();
return stream
.on('error', handleErrors)
.pipe(source(file))
.pipe(gulp.dest('./build/'))
.pipe(reload({stream:true}))
}
// listen for an update and run rebundle
bundler.on('update', function() {
rebundle();
gutil.log('Rebundle...');
});
// run it once the first time buildScript is called
return rebundle();
}
gulp.task('scripts', function() {
return buildScript('main.js', false); // this will run once because we set watch to false
});
// run 'scripts' task first, then watch for future changes
gulp.task('default', ['images','styles','scripts','resources','browser-sync'], function() {
gulp.watch('css/**/*', ['styles']); // gulp watch for CSS changes
return buildScript('main.js', true); // browserify watch for JS changes
});
Any insight would be greatly appreciated!