playing recently with bootstrap4 , sass, gulp, font awesome
have not figured out yet BrowserSync & php so this is how i use it
$php -S localhost:8000 -t f3sass this fires up project one one terminal
cd into project which when unzipped is f3sass
$gulp watch //second terminal
its a very basic set up so you can edit files & see results in a running web.very basic i'm afraid but its ok for me ; maybe others
the two files to edit are f3sass/scss/custom.scss and f3sass/node_modules/bootstrap/scss/_custom.scss
the gulp puts update in css form to ui/css i just watch gulp complete then i refresh browser; far from perfect but a start
only need to reference "style.css" as rel link in header since everything imported into that file
Only one page in project which shows at /
its got a single nav bar which collapses when browser /device shrinks toggle icon uses font awesome hamburger
link ref here
https://github.com/captain-sensible/f3sassExample