* {
  margin: 100;
  padding: 0;
  box-sizing: border-box;
}



header,
nav,
main,
footer {
  padding: 5px;
  text-align: center;
}



nav ul li {
  display: inline;
  margin: 0 10px;
}

nav ul li a {
  text-decoration: none;
  color: #000;
}


footer {
  background-color: #f3f3f3;
  padding: 10px;
  position: fixed;
  bottom: 0;
  width: 100%;
}