style.css

body {
  margin: 0;
  background-color: #002b36;
  color: #fff;
  font-family: Recursive, "Segoe UI", "Helvetica Neue", Helvetica, Roboto, "Open Sans", FreeSans, sans-serif;
}

body h1 {
  text-align: center;
}

body .concepts-container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-gap: 1rem;
  padding: 3rem;
}

body .concepts-container a {
  padding: 1rem;
  list-style: none;
  background-color: #011c23;
  transition: transform ease-in 0.3s;
  min-height: 100px;
}

body .concepts-container a:hover {
  transform: translateY(-5px);
}

body .concepts-container h5 {
  margin-top: 0;
  font-size: 1.5rem;
  font-weight: 500;
}

a {
  text-decoration: none;
  color: #fff;
}

.tag {
  background-color: #676300;
  padding: 0.25rem;
  border-radius: 0.25rem;
  display: inline-block;
  margin-bottom: 0.25rem;
}