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  <span aria-label="Indian Space Research Organisation">ISRO</span> is the space exploration body of India. Its vision is to "harness space technology for national development while pursuing space science research &amp; planetary exploration".</p>

  <span aria-label="National Aeronautics and Space Administration">NASA</span> is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and aerospace research.


                span {
  position: relative;
  color: blue;
  cursor: pointer;
  border-bottom: 2px dotted currentcolor;

  &:before {
    content: attr(aria-label);
    opacity: 0;
    position: absolute;
    top: 30px;
    right: -90px;
    font-size: 14px;
    width: 100px;
    padding: 10px;
    color: #fff;
    background-color: #555;
    border-radius: 3px;
    pointer-events: none;
    line-height: 1.4em;

  &:hover:before {
    opacity: 1;

p {
  padding: 40px;
  font-size: 1.5em;
  font-family: sans-serif;
  line-height: 1.4em;