.div-block {
  display: -webkit-box;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  width: 100vw;
  height: 100vh;
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -webkit-flex-direction: column;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-box-pack: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-box-align: center;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  background-image: -webkit-gradient(linear, left top, left bottom, from(#fff), to(#777));
  background-image: linear-gradient(180deg, #fff, #777);
}

.heading {
  color: #000;
  text-align: center;
}

.heading-2 {
  color: #000;
  text-align: center;
}

.heading-3 {
  color: #000;
  text-align: center;
}