Dark Mode and Compact Layout

The administration screens have two display controls of their own: a light or dark theme, and a compact or comfortable layout. Each person can choose for themselves on each device, so somebody working long hours in a data grid can have it the way they find easiest to read.

Where to find it

There is no panel tile. Both controls are small icons on the top row of the left-hand menu in the administration screens, beside the button that collapses the menu:

Theme: a moon or a sun. Its tooltip reads "Switch to dark mode" or "Switch to light mode".
Layout: two arrows pointing out or in. Its tooltip reads "Switch to comfortable layout" or "Switch to compact layout".

Each icon shows the mode you would get by clicking it, not the one you are in.

What the two layouts are

Compact (the default): everything in the administration screens is drawn about an eighth smaller, which is roughly what many people were doing by zooming their browser out to 85% or so. Grids show more rows and forms need less scrolling.
Comfortable: the full, browser-default size.

Compact is a proportion, not a fixed size, so somebody who has raised their browser's default text size for accessibility keeps that increase. On a touch device (a phone or tablet) compact is ignored and the full size is used, because shrinking buttons below a comfortable finger size makes them harder to hit.

Changing them

Open the Architect Panel or the Admin Panel. If the menu is collapsed to icons, expand it first: the layout icon is hidden while the menu is collapsed, because there is no room for it.
Click the moon or sun to switch theme. The change is immediate; nothing reloads.
Click the arrows to switch between compact and comfortable. Again the change is immediate.

How your choice is remembered

Both choices are stored in your browser on that device, not against your user account. That is deliberate: the choice has to be known before the page is drawn, so the screen never flashes the wrong theme first. It also means:

Another computer starts from the defaults. Set it again there.
A private window, or a browser that blocks site data, forgets the choice when it closes. The switch still works for that session.
Nobody else is affected. Your choice changes only what you see.

The defaults

Before anyone chooses, each installation has a default theme and a default layout, set by the hosting administrator in the site configuration file. Layout defaults to compact. If you have never chosen a theme and your computer's own setting asks for dark mode, the administration screens open dark; your own choice on the icon always wins.

What goes wrong and how to tell

The layout icon has disappeared: the menu is collapsed. Expand it.
The setting does not stick between visits: the browser is not keeping site data (private browsing or a privacy setting).
Compact has no effect on a tablet: by design, touch devices always get the full size.
Part of a screen stays light in dark mode: a few older screens set their own light background. Those areas are deliberately kept light, with dark text, so they stay readable rather than turning into pale text on a dark page.

Worked example

An operations administrator spends their day in the Admin Panel's work queues on a 13-inch laptop. With the compact layout they see most of a queue without scrolling, and in the evening they switch to dark mode with the moon icon. On the large monitor in the office they prefer comfortable, so they click the layout icon there once; each machine remembers its own setting, and their colleagues' screens are unchanged.

Recommendations

Tell new administrators the icons exist; many people zoom their browser instead.
Use comfortable on shared or presentation screens, where people read from further away.
Do not rely on it following a person between devices; it is per browser.
Report a screen that is hard to read in dark mode rather than living with it.