Gulpfile with browsersync serving assets withou refresh.

gulpfile.js

var gulp = require("gulp"),
    concat = require("gulp-concat"),
    minify = require("gulp-minify-css"),
    sass = require("gulp-sass"),
    sourcemaps = require("gulp-sourcemaps"),
    rename = require("gulp-rename"),
    php = require("gulp-connect-php"),
    gulpif = require("gulp-if"),
    env = process.env.NODE_ENV || "dev";

var bs = require("browser-sync").create("servername");

var paths = {
  scss: "...",
  css: "..."
};

gulp.task("css", function () {
  return gulp.src(paths.scss).
    pipe(gulpif(env == "dev", sourcemaps.init())).
    pipe(sass()).
    pipe(minify()).
    pipe(rename("app.css")).
    pipe(gulpif(env == "dev", sourcemaps.write())).
    pipe(gulp.dest(paths.mt.css));
});

gulp.task("phpserver", function () {
  php.server({
    base: "path/to/index.php",
    port: 8010,
    keepalive: true
  });
});

gulp.task("browser-sync", ["phpserver"], function () {
  bs.init({
    proxy: "127.0.0.1:8010",
    port: 8080,
    open: true,
    notify: false
  });
});

function reloadCss() {
  var css = "path/to/app.css";

  // Don't refresh browser, just serve the assets.
  bs.reload(css);
}

gulp.task("watch", ["browser-sync"], function () {
  gulp.watch(paths.scss, ["css", reloadCss]);
})

gulp.task("prod", ["css"]);

gulp.task("default", ["css", "watch"]);

Great job!