Hello Gbwaye,
Greetings of the day!
Follow the below steps to add custom CSS.
1) Please log in to the admin area
2) Go to “Appearance >> Customize >> Additional CSS”.
3) Paste the below code in “Additional CSS” and save it afterward:
@media only screen and (min-width: 768px){
.entry-content > .aligncenter, .entry-summary > .aligncenter {
margin-left: auto;
margin-right: auto;
}
}
Hope this helps.
Feel free to get in touch in case of other queries.
Thanks and Regards,
Team ProDesigns