html {
  font-family: sans-serif;
  background: #eee;
  padding: 1rem;
}

body {
  max-width: 960px;
  margin: 0 auto;
  background: white;
}

h1, h2, h3, h4, h5, h6 {
  font-family: serif;
  color: #377ba8;
  margin: 1rem 0;
}

a {
  color: #377ba8;
}

hr {
  border: none;
  border-top: 1px solid lightgray;
}

nav {
  background: lightgray;
  display: flex;
  align-items: center;
  padding: 0 0.5rem;
  gap: 0.5rem;
}

nav span {
  padding: 0.25rem 0.5rem;
  color: #377ba8;
  font-family: serif;
  font-size: 1.2rem;
}

#drop_zone {
  border: 5px solid blue;
  width: 200px;
  height: 100px;
}