Moving backgrounds behind Bayt's Home (off unless chosen in Settings).
Camera footage, each with its licence below. Bayt cuts it to a loop, scales it and removes the sound
(tools/brand/make_videos.py).

rain: Raindrops on a window, a blurred light behind.
  Author: Mixkit. Licence: Mixkit Stock Video Free License (https://mixkit.co/license/#videoFree).
  https://mixkit.co/free-stock-video/window-on-a-rainy-day-2846/

spring: Pink cherry blossoms against a blue sky, in the breeze.
  Author: Pixabay. Licence: CC0 1.0 (public domain), via Pexels.
  https://www.pexels.com/video/flowering-tree-856158/

clouds: Clouds drifting over a blue sky (time-lapse).
  Author: Extemporalist. Licence: CC0 1.0 (public domain), via Wikimedia Commons.
  https://commons.wikimedia.org/wiki/File:Timelapse_of_Clouds_over_Bellevue_Canyon.webm

lake: The sea at sunset, small waves and an island.
  Author: Pixabay. Licence: CC0 1.0 (public domain), via Pexels.
  https://www.pexels.com/video/strong-waves-during-sunset-856432/