header {
  font-size: 30px;
  text-align: center;
  width: 100%;
  border-bottom: solid 2px black;
  display: flex;
}

header div {
  padding: 20px 25px;
}

header div:nth-child(1) {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

header div:nth-child(2) {
  border-left: solid 2px black;
}

header div span {
  color: black;
  border-bottom: solid 2px black;
  margin: 0;
  font-size: 30px;
}

header a {
  text-decoration: none;
  color: black;
  cursor: pointer;
  border: none;
}

/* mobile  */
@media all and (max-width: 850px) {
  header {
    font-size: 15px;
  }

  header div span {
    border-width: 1px;
  }

  header div {
    padding: 10px 15px;
  }
}