html, body
{
      margin: 0;
      padding: 0;
      height: 100%;
}
a:link		{ color: green;  } /* liens */
a:visited	{ color: white; text-decoration: none; }
a:hover		{ color: blue; text-decoration: none; }
a:active, a:focus { color: white; }

a.fullscreen-link
{
      /*display: block;
      width: 100%;
      height: 100%;
      /*background-image: url('ton-image.jpg'); 
      background-size: cover;
      background-position: center;
      text-decoration: none; */
}
body
{
      display: flex;
      flex-direction: column;
      color: black ; background: #eee;
}
nav
{
	height: 50px; line-height: 50px;
	color: #fff; background-color: #000;
      text-align: center;
}
main
{
      flex: 1;
      display: flex;
      align-items: center; /* centrage vertical */
      justify-content: center; /* centrage horizontal */
}
footer
{
	height: 50px; line-height: 50px;
	color: #fff;  background-color: #444;
      text-align: center;
}