.box-design16 {
  margin: 20px auto;
}
.box-design16-ttl {
  background-color: #ff0000;
  color: #fff;
  padding: 0.5em 20px;
  width: fit-content;
  border-radius: 10px 10px 0 0;
  margin: 0;
  font-size: 17px;
  font-weight: bold;
}
.box-design16-txt {
  padding: 10px 20px;
  border: 2px solid #ff0000;
}