Black & Edge.css

* {
  border-radius: 0 !important;
  /* youtube */
  --yt-spec-base-background: black;
  /* twitch */
  --color-background-body: black;
  --color-background-base: black;
  --color-background-alt: black;
  --border-radius-small: 0;
  --border-radius-medium: 0;
  --border-radius-large: 0;
  --border-radius-extra-large: 0;
  --border-radius-extra-extra-large: 0;
  --border-radius-rounded: 0;
  /* bing */
  --htmlbk: black;
  /* nebula */
  --bg-color: black;
  --pageColor: black;
  --navBar: black;
  /* slack */
  --dt_color-theme-surf-inv-sec: black;
  --dt_color-plt-primary-0: 0, 0, 0;
  --sk_primary_background: 0, 0, 0;
  /* github */
  --borderRadius-medium: 0;
}

/* youtube music */
.background-gradient {
  background: black;
}

/* twitch */
.tw-root--theme-dark .chat-room {
  background-color: black !important;
}

/* bing */
#b_header, #b_content {
  background-color: black !important;
}

/* wikipedia */
body.mediawiki {
  background-color: black;
  color: white;
}
body.mediawiki *:not(a) {
  background-color: transparent !important;
  color: inherit !important;
  border: none;
}
body.mediawiki #mw-page-base, body.mediawiki h3, body.mediawiki .vector-menu-tabs {
  background-image: none !important;
  color: inherit !important;
}
body.mediawiki a {
  color: cornflowerblue !important;
}

domains.txt

www.youtube.com
x.com
twitter.com
twitch.tv
bing.com
bsky.app
music.youtube.com
nebula.tv
google.ch
google.com
wikipedia.org
de.wikipedia.org
slack.com
gist.github.com
github.com