MediaWiki:Common.css

/********* [[Template:Spoiler]] *********/
.spoiler {
  background-color: transparent;
  transition: all 0.3s;
  cursor: pointer;
  overflow:auto;
}

.spoiler > * {
  transition: all 0.3s;
}

.spoiler.hide {
  pointer-events: auto;
  background-color: var(--main-background-color); /* fallback */
  background-color: color-mix(in srgb, var(--main-background-color) 80%, transparent);
}

.spoiler.hide > * {
  pointer-events: none;
  opacity: 0;
}
 
/* If there's no js, hide then show on hover */
.spoiler.hover,
.spoiler.no-js {
  background-color: var(--main-background-color); /* fallback */
  background-color: color-mix(in srgb, var(--main-background-color) 80%, transparent);
}
.spoiler.hover > *,
.spoiler.no-js > * {
  opacity: 0;
}
.spoiler.hover:hover,
.spoiler.no-js:hover {
  background-color: transparent;
}
.spoiler.hover:hover,
.spoiler.no-js:hover > * {
  opacity: 1;
}