* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
}

/* layout */

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 20px;
}

/* top header */

.header {
  position: fixed;
  width: 100vw;
  z-index: 2;
}

.main-nav {
  border-top: #fff;
  background: #003366;
  /* as long as the tabs are gone, the empty element needs a height */
  height: 3rem;
}

.main-nav ul {
  display: flex;
  list-style: none;
  border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.main-nav li {
  border-right: 1px solid rgba(255, 255, 255, 0.2);
}

.main-nav a {
  display: block;
  padding: 14px 18px;
  color: white;
  text-decoration: none;
  font-size: 14px;
}

.main-nav a:hover {
  background: #0055a5;
}


.main-content {
  max-width: 1400px;
  margin: 0 auto;
  position: fixed;
  top: 140px;
}