Grunt sass not outputting any css

Question

This is my first time using Grunt and I'm confused why it's not outputting any css from my sass file.

Gruntfile.js

module.exports = function(grunt) {

    grunt.initConfig({
        pkg: grunt.file.readJSON('package.json'),

        sass: {
            dist: {
                options: {
                    style: 'compressed'
                },
                files: {
                    'assets/css/style.css': 'assets/sass/_styles.scss'
                }
            }
        }
    }); 

    grunt.loadNpmTasks('grunt-contrib-sass');

    grunt.registerTask('default', ['sass']);
};

When I run grunt in the terminal I receive a success message

Running "sass:dist" (sass) task

Done, without errors.

But when I look in my style.css file, nothing is there.

I'm not sure if this is necessary, but this is my sass file

_styles.scss

$font-stack: Helvetica, sans-serif;
$primary-color: #333;

body {
    font: 100% $font-stack;
    color: $primary-color;
}
nav {
  ul {
    margin: 0;
    padding: 0;
    list-style: none;
  }

  li { display: inline-block; }

  a {
    display: block;
    padding: 6px 12px;
    text-decoration: none;
  }
}

Thanks for any feedback

Answer 1

Change _styles.sass to styles.sass, it's ignoring it because it thinks this is a mixin.