<p dir="auto">Why this margin is needed?</p>
<p dir="auto">bootstrap.css (5648 line)</p>
<div class="highlight highlight-source-css notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="body.modal-open,
.modal-open .navbar-fixed-top,
.modal-open .navbar-fixed-bottom {
  margin-right: 15px;
}"><pre class="notranslate"><span class="pl-ent">body</span>.<span class="pl-c1">modal-open</span><span class="pl-kos">,</span>
.<span class="pl-c1">modal-open</span> .<span class="pl-c1">navbar-fixed-top</span><span class="pl-kos">,</span>
.<span class="pl-c1">modal-open</span> .<span class="pl-c1">navbar-fixed-bottom</span> {
  <span class="pl-c1">margin-right</span><span class="pl-kos">:</span> <span class="pl-c1">15<span class="pl-smi">px</span></span>;
}</pre></div>
<p dir="auto">When launching the modal component (<a href="http://getbootstrap.com/javascript/#modals" rel="nofollow">http://getbootstrap.com/javascript/#modals</a>) the entire content will slightly move to the left on mac OS (haven't tried it on windows yet). With the active modal the scrollbar seem to disappear, while the content width still changes.</p>
<p dir="auto">You can observer the problem on the bootstrap page</p>