- .menuitem: dark bg #334155 + light text #E2E8F0 (with !important to
override Menu widget's inline backgroundColor:white)
- .popup .vbox/.vcontainer/.vscroll: override inline white bg
- .popup h1-h6: light text color for headings
- .mini-window: dark card style for WindowsPanel dock items
- .toppopup: dark shadow variant
Sage shell defaults to dark theme but bricks.css had no dark rules,
causing light-gray text (#8a8a8a) on light backgrounds (#fafafa/#efefef)
in CRUD tables — unreadable against the dark shell.
Added comprehensive [data-theme=dark] overrides:
- body: #CBD5E1 text on #0F172A bg
- .card/.tabular/.tabular-row: dark slate backgrounds
- .inputbox/.popup/.modal/.toolbar: dark variants
- .accordion/.tabpanel/.message: dark variants
