.box-title {
  margin-bottom: 3em;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.box-title > .main {
  font-weight: 600;
  font-size: 2.2em;
  margin: 0;
  padding: 0;
}
.box-title > .sub {
  margin: 1em 0;
  padding: 0;
  font-weight: 200;
  font-size: 1em;
  max-width: 60%;
}
@media only screen and (min-width: 0) and (max-width: 767px) {
  .box-title > .main {
    font-size: 1.6em;
  }
  .box-title > .sub {
    font-size: 1em;
    max-width: 97%;
  }
}