Problem with non-inline css. (Live example)

[arkonsolutions]

Hello.

When using not inline CSS, but .css file loaded in the header page menu is not displayed, while in the browser console have this warning:

• Firefox: "WebGL warning: texSubImage: Offset+size must be <= the size of the existing specified image."
• Chrome: "[.WebGL-00005B4402385500] GL_INVALID_VALUE: Offset overflows texture dimensions."

As soon as I move the css from the file to the html page in the style tag, the menu starts displaying. But, I need to use non-inline styles, how can I avoid this error and get the menu to display?

Live example: https://aframe-htmlembed-component-css-file.glitch.me
Code editor: https://glitch.com/edit/#!/aframe-htmlembed-component-css-file

Thank you.