body {
    margin: 0;
    font-family: Lato, sans-serif;
    font-size: 1.0em;
    color: #555;
    background-color: #f5f5f5;
}
@media screen and (max-width: 800px) {
  body { font-size: 1em; }
}

@media screen and (max-width: 650px) {
  #siteNav ul { float: none; } 
}


@media screen and (max-width: 500px) {
  #siteNav ul { text-align: center;}
  #siteNav a { padding: 0.2em 0.5em; }
}

header>div, aside>div, main {
  max-width: 1200px;
  margin: 0 auto;
}
header {
  background-color: #639;
  padding: 0.5em 0.5em 1em;
}
main {
    padding: 0 0.5em 1em;
}
main p, main li {
  max-width: 50em;
}
h1 {
  font-size: 2.5em;
  color: white;
  font-weight: normal;
  margin: 0.2em 0 0.2em 0;
}
h2 {
  font-size: 2em;
  color: #639;
  margin-bottom: 0.5em;
}
h3 {
  font-size: 1.5em;
  color: #5679cd;
  margin: 0.5em 0 0.3em;
}
a {
  text-decoration: none;
}
main a {
  color: #627ed2;
  border-bottom: 1px solid #627ed2;
}
main ol li {
  margin: 0.5em 0;
}
@media screen and (min-width: 700px) {
  .deux-colonnes { columns: 2 auto; column-gap: 4em; }
  .deux-colonnes ul, .deux-colonnes li, .deux-colonnes section { break-inside: avoid; }
}