Menu navigation : problème bouton actif

Bonjour,
Je n'arrive pas à rendre actif le bouton du menu lorsque l'on est sur la page correspondante. Je ne trouve pas ce qui "cloche".
Je vous remercie par avance pour votre aide.
Cordialement,
Sophie

<header>
              <div class="nav-collapse nav-collapse_  collapse">
            <div class="aside-toggle btn-circle">
   <ul class="nav sf-menu">
    <a href="#" class="en-cours"><span>A propos</span><em>A propos</em></a>
    <a href="index-1.html"><span>Blog</span><em>Blog</em></a>
    <a href="index-2.html"><span>Portfolio</span><em>Portfolio</em></a>
    <a href="index-4.html"><span>Contact</span><em>Contact</em></a>
     </ul>

*------ header ------- */
header {
  padding: 30px 0 29px;
  z-index: 50;
}
/* navbar */
.navbar_ {
  margin: 0;
  position: relative;
}
.navbar_ .navbar-inner_ {
  padding: 0;
  margin: 0;
  border: none;
  min-height: inherit;
  filter: progid:DXImageTransform.Microsoft.gradient(enabled = false);
}
/*nav*/
.navbar_ .container {
  position: relative;
}
.nav-collapse_ {
  padding: 0;
  z-index: 10;
  float: right;
}
.nav-collapse_ .nav li {
  margin: 0;
  padding: 0;
  position: relative;
  zoom: 1;
}
.nav-collapse_ .nav > li {
  -webkit-box-shadow: none;
  -moz-box-shadow: none;
  box-shadow: none;
  background: none;
  margin-left: 22px;
}
.nav-collapse_ .nav li a {
  text-shadow: none;
  text-decoration: none;
  -webkit-transition: all 0.3s ease-in-out;
  -moz-transition: all 0.3s ease-in-out;
  -o-transition: all 0.3s ease-in-out;
  transition: all 0.3s ease-in-out;
  -webkit-box-shadow: none;
  -moz-box-shadow: none;
  box-shadow: none;
  text-transform: none;
  font-family: 'Open Sans', sans-serif;
  font-size: 20px;
  line-height: 22px;
  text-align: center;
  font-weight: 300;
  color: #1a1a1a;
}
.nav-collapse_ .nav > li > a {
  margin: 0;
  padding: 30px 0 32px;
  display: block;
  background: none;
  position: relative;
  z-index: 20;
  width: 84px;
  -webkit-border-radius: 44px;
  -moz-border-radius: 44px;
  border-radius: 44px;
}
.nav-collapse_ .nav > li > a .sf-sub-indicator {
  position: absolute;
  width: 9px;
  height: 6px;
  background: url(../img/indicator1.png) no-repeat 0 0;
  left: 50%;
  bottom: 21px;
  margin-left: -5px;
  -webkit-box-shadow: none;
  -moz-box-shadow: none;
  box-shadow: none;
  -webkit-border-radius: none;
  -moz-border-radius: none;
  border-radius: none;
}
.nav-collapse_ .nav > li.sfHover > a,
.nav-collapse_ .nav > li.sfHover > a:hover,
.nav-collapse_ .nav > li > a:hover,
.nav-collapse_ .nav > li.active > a,
.nav-collapse_ .nav > li.active > a:hover {
  background: #e85356;
  color: #ffffff;
  -webkit-box-shadow: none;
  -moz-box-shadow: none;
  box-shadow: none;
}
.nav-collapse_ .nav > li.sfHover > a .sf-sub-indicator,
.nav-collapse_ .nav > li.active > a .sf-sub-indicator {
  background-position: 0 bottom;
}
.sub-menu > a {
  position: relative;
}
.nav-collapse_ .nav ul {
  position: absolute;
  display: none;
  width: 120px;
  left: -18px;
  top: 115px;
  list-style: none;
  zoom: 1;
  z-index: 9;
  background: #ffffff;
  padding: 12px 0;
  margin: 0;
}
.nav-collapse_ .nav ul li {
  text-align: center;
}
.nav-collapse_ .nav ul li a {
  padding: 4px 0;
  display: block;
  background: none;
}
.nav-collapse_ .nav > li > ul li > a:hover,
.nav-collapse_ .nav > li > ul li.sfHover > a {
  text-decoration: none;
  color: #ffffff;
  background: #d3387b;
}
.nav-collapse_ .nav ul .sf-sub-indicator {
  display: none;
}
.nav-collapse_ .nav ul ul li a {
  color: #ffffff;
}
.nav-collapse_ .nav li ul ul li a:hover {
  text-decoration: none;
  color: #000000;
}
aside-toggle, .back-to-home {
  position: fixed;
  top: 20px;
  left: 20px;
  z-index: 100;
  -webkit-transition: 0.5s;
  -o-transition: 0.5s;
  transition: 0.5s;
}
 
.aside-toggle a, .back-to-home a {
  background: #000;
  font-size: 13px;
  width: 100px;
  height: 100px;
  line-height: 100px;
  text-align: center;
  text-transform: uppercase;
  overflow: hidden;
  position: relative;
  z-index: 10;
  color: #fff;
  display: -moz-inline-stack;
  display: inline-block;
  zoom: 1;
  *display: inline;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  -ms-border-radius: 50%;
  border-radius: 50%;
  -webkit-transition: 0.5s;
  -o-transition: 0.5s;
  transition: 0.5s;
}
.aside-toggle a:hover, .aside-toggle a:active, .aside-toggle a:focus, .back-to-home a:hover, .back-to-home a:active, .back-to-home a:focus {
  text-decoration: none;
  outline: none;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  -ms-border-radius: 50%;
  border-radius: 50%;
}
.aside-toggle a span, .back-to-home a span {
  width: 100px;
  height: 100px;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  -ms-border-radius: 50%;
  border-radius: 50%;
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  display: block;
  z-index: 8;
  -webkit-transform: scale(0);
  -moz-transform: scale(0);
  -ms-transform: scale(0);
  -o-transform: scale(0);
  transform: scale(0);
  background: #d3387b;
  background: -moz-linear-gradient(left, #d3387b 0%, #8628cd 100%);
  background: -webkit-gradient(left top, right top, color-stop(0%, #d3387b), color-stop(100%, #8628cd));
  background: -webkit-linear-gradient(left, #d3387b 0%, #8628cd 100%);
  background: -o-linear-gradient(left, #d3387b 0%, #8628cd 100%);
  background: -ms-linear-gradient(left, #d3387b 0%, #8628cd 100%);
  background: linear-gradient(to right, #d3387b 0%, #8628cd 100%);
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#d3387b', endColorstr='#8628cd', GradientType=1 );
  -webkit-transition: 0.3s;
  -o-transition: 0.3s;
  transition: 0.3s;
}
.aside-toggle a em, .back-to-home a em {
  width: 100px;
  height: 100px;
  line-height: 100px;
  position: relative;
  z-index: 10;
  font-style: normal;
  color: #fff;
  -webkit-transition-delay: .2s;
  /* Safari */
  -moz-transition-delay: .2s;
  transition-delay: .2s;
  opacity: 1;
  visibility: visible;
  -webkit-transition: 0.3s;
  -o-transition: 0.3s;
  transition: 0.3s;
}
.aside-toggle a:hover, .back-to-home a:hover {
  -webkit-transition-delay: .2s;
  /* Safari */
  -moz-transition-delay: .2s;
  transition-delay: .2s;
  background: transparent;
}
.aside-toggle a:hover em, .back-to-home a:hover em {
  color: #fff;
  opacity: 0;
  visibility: hidden;
  -webkit-transform: scale(0);
  -moz-transform: scale(0);
  -ms-transform: scale(0);
  -o-transform: scale(0);
  transform: scale(0);
}
.aside-toggle a:hover span, .back-to-home a:hover span {
  -webkit-transform: scale(1);
  -moz-transform: scale(1);
  -ms-transform: scale(1);
  -o-transform: scale(1);
  transform: scale(1);
  margin-left: 0px;
  }
}
.nav sf-menu a:active span, .en-cours a:active span {
  background-color: #91BD09;
    color: #fff;
  }

Bonjour,

il manque les <li> dans le le <ul>:

<ul class="nav sf-menu">
    <li><a href="#" class="en-cours"><span>A propos</span><em>A propos</em></a></li>
    etc.