Visually hidden (sr-only, screen reader only).

Snippet to visually hide elements without losing accessibility.

.sr-only:not(:focus):not(:focus-within) {
  position: absolute;
  pointer-events: none;
  opacity: 0;
}

Bootstrap

.sr-only:not(:focus):not(:focus-within) {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

Bootstrap's visually-hidden.scss.