When you use relative
position using right/top/bottom/left
the the button is moved from its static position leaving its actual space empty. If you want to move the button from its actual space without the empty space of the element use absolute
positioning to place the element. Read more about positioning here
CSS changes
.alert-list {
position:relative;
}
.bnt-show-alerts {
position:absolute;
right:0;
bottom:5px;
opacity:0.5;
}