styles.css

body {
  background-color: ghostwhite;
  letter-spacing: .1rem;
}

#header, #section, #footer {
  background-color: lightgrey;
}

#header {
  font-family: 'Concert One', cursive;
  border-radius: .25rem;
  width: 60rem;
  height: 16rem;
  margin: 0 auto;
  background-image: url('./dc.jpg');
  background-position: center;
  background-size: 125% 300%;
}

h1 {
  font-size: 5rem;
}

span {
  font-size: 2rem;
}

#section {
  border-radius: .25rem;
  width: 40rem;
  height: 22rem;
  margin: 0 auto;
  text-align: center;
  padding: 3rem;
  padding-top: 1.5rem;
}

.holder {
  display: inline-block;
  margin: 0 4rem;
}

.small {
  font-size: .95rem;
  font-family: 'Work Sans', sans-serif;
  font-weight: bold;
}

input {
  width: 10rem;
  height: 2rem;
  font-size: 1.1rem;
  border-radius: .25rem;
  font-family: 'Work Sans', sans-serif;
}

label {
  font-size: 1.25rem;
  font-family: 'Concert One', cursive;
}

#ans {
  font-size: 1.5rem;
  font-family: 'Concert One', cursive;
}

button {
  width: 8rem;
  height: 2rem;
  border-radius: .25rem;
  border: none;
  -webkit-transition-duration: 0.4s;
  transition-duration: 0.4s;
  background-color: slategrey;
  color: white;
  font-family: 'Work Sans', sans-serif;
  font-size: 1rem;
  margin-top: 2rem;
}
button:hover {
  background-color: black;
  box-shadow: 0 12px 16px 0 rgba(0,0,0,0.24), 0 17px 50px 0 rgba(0,0,0,0.19);
}

#section .error {
  color: white;
  font-weight: bold;
  font-family: 'Work Sans', sans-serif;
  font-size: 1.25rem;
  margin-top: 3rem;
}

#header.space, .space {
  margin-bottom: 2rem;
}

#footer {
  width: 100%;
  height: 2rem;
  position: fixed;
  padding-bottom: 1rem;
  bottom: 0;
  left: 0;
  text-align: center;
  font-family: 'Work Sans', sans-serif;
}