Dark mode
Where the switch is and what it remembers.
The sun and moon button at the top right switches between light and dark. Your choice is remembered in that browser.
If you have never touched it, Listn Visuals follows whatever your computer or phone is set to.
The image page stays dark in both modes on purpose: a dark surround is the honest way to look at a photograph, and it is what every other picture library does for the same reason.