body {
  font-family: Arial, Helvetica, sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.6;
  background-color: #f5f5f5;
  color: #333333;
}

h1, h2, h3 {
  margin-top: 0;
}

/* page header */
header {
    background-color: #333;
    color: white;
    padding: 20px;
    text-align: center;
}

/* main content */
main {
  max-width: 900px;
  margin: 65px auto;
  padding: 55px;
  background-color: #ffffff;
}

nav {
    background-color: #555;
    padding: 10px;
    text-align: center;
}

nav a {
    color: white;
    margin: 10px;
    text-decoration: none;
    font-weight: bold;
}

nav a:hover {
    color: #333;
}

img {
    max-width: 400px;
    display: block;
    margin-top: 15px;
}

footer {
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  background-color: #333;
  color: white;
  text-align: center;
}

footer a {
  color: #ffffff;
}