On single product page, default WooCommerce css use equal width for product image (left) and product summary (right). In a custom project, sometimes you want to make product summary width bigger, for example 73% for your product summary and 23% for your product image. You only need to put this CSS code to the bottom of style.css file in your chi…

style.css

/** 
 * single product page layout *
 * 23% (image) + 4% (spacing) + 73% (summary) = 100% *
**/
/* modify product image width */
.woocommerce div.product div.images, .woocommerce #content div.product div.images, .woocommerce-page div.product div.images, .woocommerce-page #content div.product div.images {
    width: 23%;
}
/* modify product summary width */
.woocommerce div.product div.summary, .woocommerce #content div.product div.summary, .woocommerce-page div.product div.summary, .woocommerce-page #content div.product div.summary {
    width: 73%;
}