.main {
  height: 100%;
  width: 100%;
  padding: 1px;
}
.text-div {
  margin: auto;
  width: 300px;
  text-align: center;
  font-family: monospace;
  color: white;
  font-size: 3em;
}

.main {
  height: 100%;
  width: 100%;
  padding: 1px;
  display: flex;
}
.text-div {
  margin: auto;
  width: 300px;
  text-align: center;
  font-family: monospace;
  color: white;
  font-size: 3em;
}

Change css to center text vertically
Change css to center text vertically
