body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 1rem;
  line-height: 1.6;
  background: #f9f9f9;
  color: #333;
}

header {
  text-align: left;
}

section {
  max-width: 800px;
  margin: auto;
}

img {
  width: 100%;
  max-width: 800px;
  height:auto;
  margin: auto;
}

footer {
  text-align: center;
  padding: 1rem;
}

a:link {
  text-decoration: none;
  color: black;
}

a:visited {
  text-decoration: none;
  color: black;
}

a:hover {
  text-decoration: none;
  color: black;
}

a:active {
  text-decoration: none;
  color: black;
}

ul.demo {
  list-style-type: none;
  margin: 0;
  padding: 0;
}