How can i add css rule to the main canvas?

Hi everyone im running into an issue where the canvas element is showing a gray highlight on iphone 6 plus.
I would like to add the following rule:

.canvas {

Where or how should i do this?

Google has answers to that.
Searching in google - is essential developers skill.

i was actually referring to if there was an internal css sheet on playcanvas part, which is currently not exposed for editing.
But thanks for the help.

You can define CSS rules, and if they will be put after default rules, then default rules will be overridden based on CSS priority logic.

Where exactly in the playcanvas dashboard do i access the css to write my rule?
or should all css be appended by script? Please do excuse me, if this sounds noobish…

Check out tutorials on this:

Thank you for the link.
I just kinda found out by accident, that you can also add css on your “createLoadingScreen” script, but not sure if this is a bad practice.