.tech-card {
  display: block;
  height: 250px;
  background-size: cover;
  background-position: center;
  position: relative;
  opacity: 0.7;
}

.tech-overlay {
  position: absolute;
  top:calc(50% - 1.5vw - 1em);
  width: 80%;
  margin-left:10%;
  background: rgba(3, 0, 0, 0.8);
  text-align: center;
  padding: 1em 0;
  color:#fff;
}

.tech-overlay h3{
    height:3vw;
    margin-bottom:0;
    margin-right:1em;
    margin-left:1em;

}