I want to change my blog post like this

Hi there,

try this:

body:not(.single):not(.page) .inside-article {
    display: grid;
}

body:not(.single):not(.page) .post-image {
    grid-column: 1;
    grid-row: 1 / 5;
    margin-right: 20px !important;
}

body:not(.single):not(.page) .entry-header {
    grid-column: 2;
    grid-row: 1;
}

body:not(.single):not(.page) .post h2 {
    font-size: 20px;
}
body:not(.single):not(.page) .entry-summary {
    font-size: 14px;
}

It is looking good on desktop but on mobile it is not looking good

How do you want it displayed on mobile with the image still aligned left or above the content?

In mboile view i wants to dispaly full image

Thankyou, I have fixed it up...

Awesome - looks great - glad to be of help.