body {
  font-family: sans-serif;
  max-width: 700px;
  margin: 40px auto;
  padding: 0 1rem;
  line-height: 1.6;
  color: #333;
}
nav a {
  margin-right: 15px;
  text-decoration: none;
  color: #007acc;
}
nav a:hover {
  text-decoration: underline;
}
header, footer {
  margin-bottom: 2rem;
  text-align: center;
}
footer {
  font-size: 0.9rem;
  color: #999;
}
main ul {
  list-style: disc;
  padding-left: 20px;
}

img {
  border: 1px solid #ccc;
  border-radius: 4px;
  padding: 4px;
  background-color: #f9f9f9;
  max-width: 100%;
  height: auto;
  margin-bottom: 1rem;
}

video {
  border: 1px solid #ccc;
  border-radius: 4px;
  padding: 4px;
  background-color: #f9f9f9;
  max-width: 100%;
  height: auto;
  margin-bottom: 1rem;
}