body {
  background-color: lightblue;
}

h1 {
  font-family: Arial;
  color: yellow;
  font-size: 20px;
}

h2 {
  font-family: Arial;
  color: white;
}


p {
  font-family: Arial;
  font-size: 20px;
  color: black;
}




body {
    margin:0;
}


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



header, footer {
    padding: 10px;
    color: white;
    background-color: grey;

}



ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: grey;
    position: fixed;
    top: 0;
    width: 100%;
}

li {
    float: left;
}

li a {
    display: block;
    color: white;
    text-align: center;
    padding: 17px 45px;
    text-decoration: none;
    font-size: 18px;
    font-family: Arial;
}

li a:hover:not(.active) {
    background-color: black;
}

.active {
    background-color: black;
}

section {
    margin: 35px;
    padding: 12px;
    background-color: grey;
}

article {
    margin: 10px;
    padding: 20px;
    background-color: lightblue;
}