css justify boxes

HTML

<div class="container">
    <div class='element'>Box1</div>
    <div class='element'>Box2</div>
    <div class='element'>Box3</div>
    <div class='element'>Box4</div>
    <div class='element'>Box5</div>
    <div class='element'>Box6</div>
</div>
<br/>
<input id='new_div' type='button' value='add div'>

CSS

* {
  margin: 0;
  padding: 0;
}
.container {
  background: orange;
  overflow: auto;
  display: block;
  min-width: 165px;
}
.container > div {
  margin: 20px 0 20px 0;
  width: 164px;
  height: 100px;
    color: #fff;
    text-align: center;
  background: blue;
  float: left;
}

JavaScript

$(function() {
  // Call function when DOM is ready
      settingsAlignment();

    $(window).resize(function() {
          // Call function on window resize
            settingsAlignment();
        })

    $('#new_div').click(function() {
        box_number = $('.element').size();
        box_add = box_number + 1;
        $('.container').append($('<div class="element">Box'+ box_add + '</div>'))
        settingsAlignment();
    })
    
function settingsAlignment() {
    // calculation of ul's padding-left and li's margin-right
    var settingsUl = $('.container');
        settingsLi = $('.element');
        ul_width = settingsUl.outerWidth(true);
        item_width = settingsLi.width();
        min_gap = 7;
        effective_item_width = item_width + min_gap;
        items_in_row = Math.floor((ul_width - min_gap) / effective_item_width);
        gaps_sum = ul_width - items_in_row * item_width;
        new_gaps = gaps_sum / (items_in_row + 1);
        item_margin = Math.floor(new_gaps);
        row_width = (item_width + item_margin) * items_in_row - item_margin;
        console.log(row_width + '= row_width');
        console.log(ul_width + '= ul_width');
        ul_left_padding = Math.ceil((ul_width - row_width) / 2);
        console.log(ul_left_padding + '=ul_left_padding');
        settingsUl.css('padding-left', ul_left_padding + 'px');
        settingsLi.css('margin-right', item_margin + 'px');
      console.log(settingsLi);
  }
});