body {
  /* background-color: red; */
  font-family: 'Optima', sans-serif;
  margin: 0;
}

main {
   max-width: 800px;
   padding: 1em;
   margin: 0 auto;
   /* margin-left: 250px; */
}

header {
  text-align: center;
  position: relative;
}

header img {
  width: 100px;
  position: absolute;
  left: 60px;
  bottom: 0;
}

h1 {
  font-family: sans-serif;
  font-size: 2.5em;
}

h2, h3, h4, h5, h6 {
  padding-top: 1em;
  font-family: serif;
  text-decoration: underline;
}

nav {
  text-align: center;
  /* position: fixed;  */
  /* left: 10px;  */
  /* top: 20em;  */
  /* width: 20%; */
}

nav ul {
  padding: 1em;
  background-color: black;
  list-style-type: none;
}

nav li {
  display: inline-block;
}

nav a {
  color: white;
  display: block;
  text-decoration: none;
  padding: .5em;
}

nav a:hover {
  background: blue;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th {
  background: black;
  color: white;
}

th, td {
  padding: .5em;
}

table, th, td {
  border: solid 1px black;
}

tr:nth-child(even) {
  background: #CCC;
}

a {
  color: red;
}

a:hover {
  background: yellow;
}

footer {
  background: grey;
  color: white;
  font-size: .5em;
  padding: 1em;
}

footer h2 {
  padding: 0;
  margin: 0;
}