· From CSS hide-and-seek
The .sr-only class is a utility class aiming at visually hiding the element while keeping it accessible to assistive technologies such as screen-readers. It relies on a carefully designed combination of declarations for maximum support, and !important bangs to make sure to override any more specific CSS.
.sr-only {
border: 0 !important;
clip: rect(1px, 1px, 1px, 1px) !important;
-webkit-clip-path: inset(50%) !important;
clip-path: inset(50%) !important;
height: 1px !important;
overflow: hidden !important;
margin: -1px !important;
padding: 0 !important;
position: absolute !important;
width: 1px !important;
white-space: nowrap !important;
}