By default, Unity will resize the canvas resolution to match the style resolution, along with the devicePixelRatio to scale the resolution for HDPI screens. This is because the canvas attributes control the WebGL resolution in the browser, and Unity matches the resolution to how it's displayed. For example if you switch to full screen, the resolution will be automatically adjusted to that new size. You can turn off this behavior with `config.matchWebGLToCanvasSize = false;` in the template html, which will give you independent control of the style and canvas resolution.