header ul {
  text-align: center;
  border-bottom: 1px solid #e8e8e8;
}

header ul li {
  display: inline-block;
}

header ul li a {
  font-size: 14px;
  margin: 0 .5em;
}

h1 {
  font-size: 40px;
  font-weight: 700;
  margin-bottom: 20px;
}

button {
  background: black;
  color: white;
  padding: .5em;
  border-radius: 5px;
}