I need help with following:

Hi there,

1. this CSS will center the entry title on mobile:

@media (max-width: 768px) {
    .single-post .entry-title {
        text-align: center;
        border-bottom: 1px solid #000;
    }
}

If you want to center the entry meta as well then change:

.single-post .entry-title { to .single-post .entry-title, .single-post .entry-meta {

2. Is this also on the single post?

Hey, David!

Thanks for the help.

2. I need to customize on all posts.

Sorry what i mean was is this to be displayed just on the post or in the blog / archive ( ie. list of posts)?

Yes, it should be on the single blog post and I will think for the archive as well so you can help me for both.

I have another question, How can I create Slide-Out Sidebar just like a slide-out menu?

So this article covers how to make the post meta changes:

https://docs.generatepress.com/article/entry-meta-style/

You could use the Off Canvas Panel ( Slide Out navigation as it was called prior to GPP 1.8 ). It has its own widget area.

Thanks for the fast reply, I have checked out but couldn't found Widget area.
can you please guide me on how to do this?

I found the widget area in Appearance>widgets, I was looking for it in the Menu section.

Thanks for the help.

I love GP theme and recommends others to use this.

Awesome - glad we could be of help

Hi, David!

All the codes you gave are working good, Thanks to you for this.

I have one query, How can I change post meta size to fit it every mobile screen?

Like it should be shown in a line, Not like this image...
https://drive.google.com/file/d/1-4gYhyKd_fOTxL2jcCg0oKYFDJEky1Zk/view?usp=drivesdk

And how can I add a small line after the centred post title in mobile view only?

You could try reducing the mobile font size like so:

@media (max-width: 420px) {
    .single-post .entry-meta {
        font-size: 16px;
    }
}

Thanks for this code, It is working as I needed...

Loving GeneratePress Support...😍😍😍

And please let me know, how can I add a small line after the centred post title in mobile view only?

Edited David's code here:
https://generatepress.com/forums/topic/i-need-help-with-following/#post-906748

Hey, Leo!

I added this CSS
@media (max-width: 768px) {
.single-post .entry-title, .single-post .entry-meta {
text-align: center;
border-bottom: 1px solid #000;
}
}

it is working border for both title and meta, I want to show only after the meta. And also how can I control the width of the line?

It is also showing border after the comments meta like date, name etc...