/* Adjust the width of the billing details section */
.woocommerce-checkout .col2-set .col-1,
.woocommerce-checkout .col2-set .col-2 {
    width: 100%; /* Change this value as needed (e.g., 60%, 70%, etc.) */
    float: left;
}

/* Adjust the width of the billing details form fields */
.woocommerce-billing-fields .form-row {
    width: 100%; /* Change this value as needed */
}