Edit in JSFiddle

$(document).ready(function(){
	$(".menu-toggle").click(function(){
  	$(".site-menu").toggleClass("toggled");
  });
});

@import 'https://fonts.googleapis.com/css?family=Raleway:100';
@import 'https://fonts.googleapis.com/css?family=Open+Sans';
*{
  transition:all 0.2s ease 0.0s;
  font-family: 'Open Sans', sans-serif;
}
body{
  padding:0;
  margin:0;
}
.site-menu{
  position:fixed;
  background-color:#312c32;
  width:50px;
  height:100%;
  overflow: hidden;
  -webkit-box-shadow: 11px 0px 31px 0px rgba(0,0,0,0.18);
-moz-box-shadow: 11px 0px 31px 0px rgba(0,0,0,0.18);
box-shadow: 11px 0px 31px 0px rgba(0,0,0,0.18);
}
.site-menu.toggled{
  width:190px;
}
.site-menu .menu-toggle{
  text-align:center;
  background-color:#98dafc;
  background-color:#daad86;
  padding:10px;
  margin-bottom:10px;
  cursor:pointer;
}
.site-menu .menu-toggle:hover{
  background-color:#88caec;
  background-color:#ca9d76;
}
.site-menu .menu-toggle .fa{
  font-size:20px;
  color:#ffffff;
  color:#312c32;
}
.site-menu.toggled .menu-toggle .fa{
  transform:rotate(180deg);
}
.site-menu ul{
  padding:0;
  margin:0;
  list-style:none;
  width:100%;
  overflow: hidden;
}
.site-menu ul li{
  overflow: hidden;
  padding:15px 15px 15px 15px;
  white-space: nowrap;
}
.site-menu.toggled ul li{
  padding:15px 15px 15px 30px;
}
.site-menu ul li a{
  color: #daad86;
  text-decoration:none;
  font-size: 25px;
  opacity:0.5;
  font-family: 'Raleway', serif;
}
.site-menu ul li a:hover,
.site-menu ul li.active a{
  color:#98dafc;
  opacity:1;
}
.site-menu ul li a .fa{
  margin-right:15px;
  font-size:18px;
  width:20px;
  text-align:center;
}
.content{
  margin-left:50px;
  padding:15px;
  background-color:#ffffff;
  color:#312c32;
}

<div class="site-menu">
  <div class="menu-toggle">
    <i class="fa fa-chevron-right"></i>
  </div>
  <ul>
    <li class="active">
      <a href="#">
        <i class="fa fa-home"></i>Home
      </a>
    </li>
    <li>
      <a href="#">
        <i class="fa fa-info-circle"></i>About
      </a>
    </li>
    <li>
      <a href="#">
        <i class="fa fa-camera"></i>Gallery
      </a>
    </li>
    <li>
      <a href="#">
        <i class="fa fa-envelope"></i>Contact
      </a>
    </li>
  </ul>
</div>

<div class="content">
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.<br><br>
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
</div>