Using WebStorm 10, how do I include image/font files within my current project?

Someone please help me before I take a golf club to my monitors.

I know this question will sound absurdly easy to most, but for the life of me I cannot include an image file (or any other outside file) in my WebStorm 10 project directory. When I copy the image from my desktop to the WS environment, I get a complaint that the file "is not included in the current project" even though the destination folder shows the image file I just imported. Consequently, WS refuses to cooperate with my src references when trying to declare a background image in my stylesheet.

The JetBrains help guide conveniently skips this point and I seem to be the only person on the internet with this question. So please... treat my ignorance like a band-aid and make the sting a quick one. What am I missing?

If it makes any difference I included the bare bone CSS code I used to test the imported files, but as I said the problem isn't in the code- it's the inability to resolve the resource.

@font-face {
    font-family: "UpperEastSide",
    src: url(\[project_name]\fonts\UpperEastSide.ttf);
}

body {
    background: url("\[project_name]\images\background.jpg");
}