Scrollbar offset

How to prevent any offset from a scrollbar

HTML

<body>
    <div id="wrapper">
        <aside class="displayed">
            <img src="resources/images/self.jpg" alt="self" />	<address>
				<strong> XXX </strong> <br />
				21 ans <br />
				<em class="email"> XXX </em> <br />
				<em> <a href="http://XXX"> XXX </a></em>
			</address>

            	<h1> Développeur Informatique </h1>

        </aside>
        <div class="main">
            <section>	<a href="#educ" data-target="education-content" class="extender"> <h2> Formation </h2> </a>

                <div class="content education-content">
                    <ul class="multiline-list left-margin">
                        <li>	<span class="date"> 2013 - 2015 </span> 
                            <br />	<span class="diploma"> Diplôme de Bachelor en Science de l'Ingénieur </span> 
                            <br />	<span class="comment"> 90 ects validés (3 semestres)</span> 
                            <br />	<span class="location"> ENSEIRB-MATMECA, Talence</span> 
                            <br />
                        </li>
                        <li>	<span class="date"> 2011-2013 </span> 
                            <br />	<span class="diploma"> DUT Informatique</span> 
                            <br />	<span class="comment"> 5ème de promotion </span> 
                            <br />	<span class="location"> IUT de Bordeaux I, Gradignan</span> 
                            <br />
                        </li>
                        <li>	<span class="date"> 2011 </span> 
                            <br />	<span class="diploma"> Baccalauréat Scientifique</span> 
                            <br />	<span class="comment"> Section Européenne <br />
												   Mention Assez Bien</span> 
                            <br />	<span class="location"> Lycée Jay de Beaufort, Périgueux</span> 
                            <br />
                        </li>
                    </ul>
                </div>
            </section>
            <section>	<a...

CSS

/******************/

/****** BASE ******/

/******************/
 * {
    color: rgb(100, 100, 100);
    font-family: Roboto, sans-serif;
}
html {
    height: 100%;
}
body {
    background: rgb(25, 25, 25);
}
a {
    color: rgb(150, 150, 150);
    text-decoration: none;
}
a:hover {
    font-weight: bold;
}
.email {
    unicode-bidi: bidi-override;
    direction: rtl;
}
#wrapper {
    box-sizing: border-box;
    margin: 0 auto;
    max-width: 960px;
    position: relative;
}
/********************/

/****** LAYOUT ******/

/********************/
 .left-align {
    padding-left: 40px;
}
/******************/

/****** MAIN ******/

/******************/
 .main {
    background: rgb(15, 15, 15) url("images/background.png") no-repeat 100% top;
    box-sizing: border-box;
    padding: 20px;
}
/****** ASIDE ******/
 aside {
    background-color: rgb(15, 15, 15);
    box-sizing: border-box;
    padding: 20px;
    width: 250px;
}
aside.displayed {
    margin-left: -260px;
    position: fixed;
}
aside img {
    box-sizing: border-box;
    display: block;
    height: 200px;
    width: 200px;
    margin: 0 auto;
}
address {
    font-style: normal;
    line-height: 1.2em;
    margin-top: 20px;
}
address strong {
    color: rgb(0, 204, 204);
    display: block;
    font-weight: bold;
    font-size: 1.5em;
    text-align: center;
}
address em {
    font-style: normal;
}
address a {
    display: block;
    font-size: 1.2em;
    padding: 10px;
    text-align: center;
}
h1 {
    color: rgb(0, 175, 100);
    display: block;
    font-size: 1.5em;
    font-weight: bold;
    text-align: center;
    text-transform: uppercase;
}
/****** SECTIONS ******/
 h2 {
    color: rgb(0, 204, 204);
    display: inline-block;
    font-size: 1.5em;
    font-weight: bold;
    margin: 0 0 20px;
}
.content {
    margin-bottom: 15px;
}
ul {
    list-style: none;
    margin: 0;
}
.multiline-list > li:nth-child(n+2) {
    margin-top: 1.2em;
}
/*** education & work experience ***/
 .date {
    color: rgb(0,...

JavaScript

function onReady() {
    /*** extendable sections ***/
    $(".extender").click(function () {
        var target = $(this).attr('data-target');
        $('.' + target).slideToggle();
    });
}
$(document).ready(onReady);