Javascript not displayed by user agent stylesheet

I've got some Javascript code that displays a canvas in my browser which I want to run. It's on a local machine not a server yet. I cannot get the Javascript to be displayed. It's overridden by the User Agent Stylesheet:

script {
    display: none;
}

I've tried overriding the User Agent Stylesheet by adding some code to my CSS file:

script {
    display: block;
}

The result was that all my JavaScript code wasn't executed anymore but displayed in the browser. I've tried disabling the User Agent Stylesheet in Chrome (version 51) but cannot find such an option. I've tried normalizing/resetting the style-sheet but this didn't help either.

I've putting the code in a separate JavaScript file and excute the code from there but this didn't help either. I've been looking at and Googling it for hours but haven't found a successful answer yet.

Does anybody have a answer for this?