*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.caption {
  position: absolute;
  left: 0;
  top: 10%;
  width: 100%;
  text-align: center;
  color: #000;
  font-size: 18vw;
}

.caption span.border {
  background-color: #111;
  color: #fff;
  padding: 18px;
  font-size: 25px;
  letter-spacing: 10px;
}

@media only screen and (max-width: 900px) {
  .caption {
    top: 30%;
  }
}