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//Do not forget the absolute position!
.parentDiv{
position: relative;
}
.insideParentDiv{
position: absolute;
}
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#wrapper { width: 300px; background: orange; margin: 0 auto; position: relative; }
#feedback { position: fixed; right: 0; top: 120px; }
<div id="wrapper">
<a id="feedback" href="#">Feedback</a>
</div>