Hello There,
It is not a conflict with the theme. Please understand that we do not support One Page Check out plugin. This plugin must have it’s own independent styling. Yes it should work out of the box which is also working perfectly by the way. The only problem is that since X theme does not support this plugin, it looks aweful at the moment because X does not recognize all those elements wrapping the form elements. To resolve, this you can make use of the code give by Christopher:
@media (min-width:979px){
p#billing_first_name_field, p#billing_last_name_field, p#billing_email_field, p#billing_state_field {
width: 48%;
float: left;
}
.woocommerce-billing-fields {
width: 48%;
float: left;
}
p#billing_company_field input, p#billing_address_1_field input, div#s2id_billing_country, p#billing_address_2_field input, p#billing_city_field input {
width: 85% !important;
}
p#order_comments_field textarea {
width: 50%;
}
div#s2id_billing_state {
width: 91% !important;
}
}
I would highly suggest that you update X theme to 6.1.5 and Cornerstone to 3.1.5. These latest version has more styling controls over the latest WooCommerce version. If there is a need, we may be able to provide additional css code to fix minor cosmetic issues with the plugin.
Please let us know how it goes.