:root {
  --light: #f5f5f5;
  --dark: #3c3c3c;
  --primary: #087e8b;
  --secondary: #ff5a5f;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Caveat', cursive;
  color: var(--light);
}

html {
  display: flex;
  flex-flow: column nowrap;
  overflow: hidden;
  height: 100vh;
}

div {
  display: flex;
  justify-content: center;
  align-items: center;
}
.upper {
  background: var(--primary);
  height: 50vh;
}
.lower {
  background: var(--secondary);
  height: 50vh;
}

h1 {
  font-size: 6rem;
  font-weight: 400;
}

h3 {
  font-size: 2.5rem;
  font-weight: 400;
}

#call {
  position: fixed;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  background: var(--light);
  color: var(--dark);
  font-size: 3.25rem;
  padding: 0.75rem 5rem;
  border-radius: 0.8125rem;
  box-shadow: 0px 4px 4px 0px rgba(0, 0, 0, 0.25);
  text-decoration: none;
  transition: transform 0.125s ease-in-out;
}

#call:hover {
  transform: translate(-50%, -50%) scale(0.95);
}

@media only screen and (max-width: 1000px) {
  #call {
    font-size: 2.4rem;
    padding: 0.75rem 3rem;
  }
}

@media only screen and (max-width: 700px) {
  html {
    font-size: 12px;
  }
  #call {
    font-size: 2.2rem;
    padding: 0.75rem 2rem;
  }
}