Centering results of shortcode

What coding do I need to enter to center the results of the shortcode: [slideshow id=1] below? The Div tags above the shortcode layout the cell in which the results of the shortcode are contained in. Since the cell is 67% wide I’m not sure how to go about this.

Thank you

<div class="art-content-layout">
<div class="art-content-layout-row">
<div class="art-layout-cell layout-item-0" style="width: 100%;">
<div class="art-content-layout layout-item-old-0">
<div class="art-content-layout-row">
<div class="art-layout-cell layout-item-old-1" style="width: 67%;">

[slideshow id=1]

</div>