CSS breaks Lumo dark mode

[stefanuebe]

The idle.css defines a different background color than the default one of the lumo dark theme. This leads to a white-ish background, when using the dark theme.

Not sure if the addon should apply these styles at all. In most applications, the background color is defined by a global styling, therefore I would leave that part out. Also adding bg color transitions might be seen as some unwanted style injection :)

If someone wants to have stylings based on the state, they can easily add these using the given css class names.

[stefanuebe]

Workaround:

body.useractive,
body.userinactive {
    background-color: var(--lumo-base-color);
    transition: background-color 0s;
}