Sparkling Blog Post Style

Hello guys,

I’ve been spotted as spammers because of several editing on my previous topic. I got a problem in uploading an image on the topic. So I just give the link where I upload my images.

Regarding this topic, I have a question,

This is my blog post:

Before it, as long as I remember, I edited the style.css in Post Styling like this one:
.post-inner-content {
padding: 3px 50px;
background-color: transparent;
border: none;
border-top: none;
.post-inner-content:first-child {
border-top: none;

I did it because I just want to make the full-width page, just same as the background colour, like this one (

How to make Blog Post style back like Sparkling demo ( but still keep the full-width page style like I did?

Thank you for your help.

Best wishes,