{
  margin: 0;
  padding: 0;
}

header {
  background-color: cadetblue;
  display: flex;
  flex: auto;
}

header img {
  width: 100px;
  flex: 0;
}
main {
  padding: 4em;
}
header nav {
  display: flex;
  flex: auto;
  justify-content: space-between 2em;
}

header nav a {
  text-transform: uppercase;
  text-decoration: none;
  color: black;
  transition: 0.5s;
  :hover {
    color: red;
    font-weight: bold;
  }
}
footer {
  background-color: cadetblue;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
}