body{
    width: 80%;
    clear: both;
    margin: auto;
}

tag{
    font-weight:bold;  
}

tag:before{
    font-weight: bold;
    content:'<';
}

tag:after{
    font-weight: bold;
    content:'>';
}

.l1:before{
    margin-left: 40px;
}

.l2:before{
    margin-left: 80px;
}

.l3:before{
    margin-left: 120px;
}

.banner{
    width: 150px;
}

body{
    background-color: #d7fdff;
}

header{
    border: black;
    background-color: #fff8e9;
}

nav{
  background-color: MediumSpringGreen;
}

nav ul{
  padding: 0;
  list-style:none;
}

nav ul li{
  padding:1em;
  text-align: center;
  display: inline-block;
  background-color: green;
  text-decoration: none;
  color: white;
}

nav ul li:hover{
  background-color: AquaMarine;
}

nav ul li:hover a{
    color: black;
}

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

footer{
    margin: 2%;
    text-align: center;
    background-color: black;
    color: white;
    border: 2px solid tan;
    padding: 0.8em;
}

h1,h2,h3,h4{
    text-align: center;
    color: navy;
}

h6{
    font-size: 12pt;
    margin: 5%;
}

p{
    font-family: 'Courier New', Courier, monospace;
    text-align: justify;
    padding-left: 5em;
    padding-right: 5em;
    margin: auto;
}

section{
    display: inline-block;
    padding: 3%;
    width: 75%;
    background-color: #fff8e9;
}

aside{
    padding: 1%;
    display: inline-block;
    align-content: center;
    text-align: center;
    width: 15%;
}

article{
    text-align: center;
    align-content: center;
    text-align: left;
}

ol{
    padding-left: 10em;
    padding-right: 5em;
}

.ejem{
    margin: 5%;
    display: inline-block;
    background-color: silver;
    height: 100%;
}