body::before {
  content: "We've noticed you are using an outdated browser. Some content may not play or display correctly. Please consider switching to a modern browser such as Chrome or Firefox.";
  display: block;
  margin: auto;
  max-width: 1200px;
  padding: 1rem 0;
}

.header {
  margin: auto;
  max-width: 1200px;
  min-height: 8rem;
  position: relative;
}

.header-logo {}
.header-sign-in {
  left: 50%;
  position: absolute;
  top: 0;
}
.header-social {
  left: 80%;
  position: absolute;
  top: 0;
}
.header-buttons {
  left: 50%;
  position: absolute;
  top: 2rem;
  width: 50%;
}
.header-buttons ul li {
  display: inline-block;
  width: calc(33.33% - .5rem);
}

#header-menu {
  position: absolute;
  top: 5rem;
}
#header-menu li {
  display: inline-block;
  margin: 0 1rem;
}