html {
  color: #006700;
}

html, body {
  padding: 0;
  margin: 0;
}

.container {
  max-width: 1600px;
  padding: 1rem;
  margin-left: auto;
  margin-right: auto;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, 315px);
  justify-items: center;
  align-items: center;
}

h2 {
  margin-top: 3rem;
  margin-bottom: 1rem;
}

h3 {
  margin-top: 2rem;
}

h4 {
  margin-bottom: 0.25rem;
}

ul {
  margin-top: 0;
}

hr {
  border: 0;
  border-top: 1px solid lightgray;
}

img {
  max-width: 100%;
  height: auto;
}

a[target="_blank"] img {
  cursor: zoom-in;
}

.reference:target {
  background-color: #ffff00;
}

@media screen and (max-width: 550px) {
  .grid {
    grid-template-columns: repeat(auto-fill, 100%);
  }
}