style.css

body {
  font-family: sans-serif;
  background-color: #eee;
  padding: 0;
  margin: 0;
}

section > * {
  margin: 1em auto;
  max-width: 640px;
  box-sizing: border-box;
}

section > blockquote {
  padding: 0 32px;
  background-color: #eee;
  overflow: hidden;
}

h1 {
  font-size: 25pt;
}

h3 {
  font-size: inherit;
}

#terms, #privacy {
  position: absolute;
  background-color: white;
  margin: 64px 0 0;
  border-top: 1px solid #888;
  width: 100%;
}

#terms::before, #privacy::before {
  display: block;
  position: absolute;
  top: -32px;
  height: 15px;
  border: 1px solid #888;
  border-bottom: none;
  background-color: white;
  padding: 8px 0;
  text-align: center;
  width: 190px;
}

#terms::before {
  content: "Terms of Service";
  left: calc(50% - 320px);
}

#privacy::before {
  content: "Privacy Policy";
  left: calc(50% - 120px);
}

body.terms #terms, body.privacy #privacy {
  z-index: 1;
}

body.privacy #terms > *, body.terms #privacy > * {
  display: none;
}

@media screen and (max-width: 650px) {
  section > * {
    width: 100%;
    padding-left: 8px;
    padding-right: 8px;
  }
  #terms::before, #privacy::before {
    width: calc(50% - 16px);
  }
  #terms::before { left: 8px; }
  #privacy::before { right: 8px; left: auto; }
}