.header-body {
  width: 100%;
  position: fixed;
  top: 0;
  left: 0;
}

.header {
  width: 1200px;
  display: flex;
  height: 100px;
  align-items: center;
  justify-content: space-between;
  margin: 0 auto;
}

.header .nav a {
  text-decoration: none;
  font-size: 16px;
  color: #ffffff;
  margin-left: 40px;
}

.header .nav .bottom-line {
  border-bottom: 2px solid #ffffff;
  padding-bottom: 8px;
}