Hello,

Please, use this css in your custom css. To add custom css, please, follow this guide: https://www.joomshaper.com/documentation/helix-framework/custom-code-css-js-meta

.sppb-addon-content.nano {
    position: relative;
}

.sppb-article-readmore-wrapper {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    text-align: center;
    margin: 10px 0;
}

Thanks,