Debug a Random Background Color Changer

Camperbot is learning JavaScript and has tried to build their own Random Background Color Changer. However, they have made a few mistakes along the way. **Objective:** Fulfill the user stories below and get all the tests to pass so the lab is functioning properly. **User Stories:** 1. You should fix the syntax errors in the `darkColorsArr` array. 1. You should fix the `ReferenceError` thrown when the `math` object is referenced inside the `getRandomIndex` function. 1. You should round down `randomIndex` to the nearest whole number. 1. You should update the value of the `body` variable to use the correct method name and fix the related `TypeError`. 1. You should fix `bgHexCodeSpanElement` so that it correctly selects the element with the `id` of `bg-hex-code`. 1. You should modify the `color` variable inside `changeBackgroundColor` so that it is set to a random color from the `darkColorsArr` array. 1. You should update the `btn` variable so that it targets the button element. Open up the `index.html` to see the correct `id` name for that button element. 1. You should fix the line that adds an event listener for the `click` event to `btn` by passing a reference to the `changeBackgroundColor` function to the method. 1. Your background should randomly change to one of the colors in `darkColorsArr` each time the `#btn` is clicked.