Hi Nikita,

Thanks for contacting WPClever Support Forum. Sorry for the delayed response. Our system has run into some unknown issues so our Support Forum has not been working properly recently. Today it's finally working back again so I am able to process your ticket.

I have assigned one of our developers to help you with that. He’ll be looking into your question and responding with specific instructions as soon as possible. 

Please stay patient as we're having very heavy workloads, it might take some time for our developers to reach back.

Best regards.

Hi Nikita,

Please add below CSS code to WP-Admin → Appearance → Customize → Additional CSS:

.woofc-checkout-form .container {
    padding-left: 0 !important;
    padding-right: 0 !important;
}
.woofc-checkout-form .container .row {
    margin-left: 0 !important;
    margin-right: 0 !important;
}
.woofc-checkout-form .container .row > div {
    width: 100% !important;
}
.woofc-checkout-form .form.checkout .woocommerce-billing-fields__field-wrapper #billing_address_1_field, .woofc-checkout-form .form.checkout .woocommerce-billing-fields__field-wrapper #billing_city_field, .woofc-checkout-form .form.checkout .woocommerce-billing-fields__field-wrapper #billing_country_field, .woofc-checkout-form .form.checkout .woocommerce-billing-fields__field-wrapper #billing_first_name_field, .woofc-checkout-form .form.checkout .woocommerce-billing-fields__field-wrapper #billing_address_2_field, .woofc-checkout-form .form.checkout .woocommerce-billing-fields__field-wrapper #billing_city_field, .woofc-checkout-form .form.checkout .woocommerce-billing-fields__field-wrapper #billing_first_name_field, .woofc-checkout-form .form.checkout .woocommerce-billing-fields__field-wrapper #billing_last_name_field, .woofc-checkout-form .form.checkout .woocommerce-billing-fields__field-wrapper #billing_state_field {
    margin-right: 0;
    flex-basis: auto;
}
.woofc-checkout-form #payment li label, .woofc-checkout-form #shipping_method li label {
    width: 100%;
}

And the result (screen record video) https://www.screencast.com/t/6r4HRI6RNoS