function reduireSection() {
  var div = document.getElementById('linux'),
    display = getComputedStyle(div, null).display;

  if (display == "block") {
    document.getElementById("linux").style.display = "none";
    document.getElementById("bouttonReduireSection").className = "icon-angle-down";
  } else {
    document.getElementById("linux").style.display = "block";
    document.getElementById("bouttonReduireSection").className = "icon-angle-up";

  }
}