Can I change site logo for blog landing page and blog posts only?

Site URL: https://www.guesthouselit.com

Hi everyone!

First-time poster here. Long-time Squarespace user. I'm interested in knowing how to change the logo on the top of the left sidebar on my blog pages only. The site is www.guesthouselit.com. I want the blog logo to be an inversion of the regular site logo, attached here. 

Can anyone recommend a solution? I assume I use the "Page header code injection" and "Post blog item code injection" features, but I can't determine what to paste in there. (I'm a newbie to CSS and HTML, so simplicity is appreciated.)

Many, many thanks,

Jane

50 minutes ago, SeeThroughPie said:

Site URL: https://www.guesthouselit.com

Hi everyone!

First-time poster here. Long-time Squarespace user. I'm interested in knowing how to change the logo on the top of the left sidebar on my blog pages only. The site is www.guesthouselit.com. I want the blog logo to be an inversion of the regular site logo, attached here. 

Can anyone recommend a solution? I assume I use the "Page header code injection" and "Post blog item code injection" features, but I can't determine what to paste in there. (I'm a newbie to CSS and HTML, so simplicity is appreciated.)

Many, many thanks,

Jane

add this to Design->Custom CSS

.collection-type-blog #logo .logo.image img {
  opacity: 0;
}
.collection-type-blog #logo .logo.image a:after {
  position: relative;
  display: block;
}
.collection-type-blog #logo .logo.image a:after {
  content: '';
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  background-image: url(//content.invisioncic.com/p289038/monthly_2021_04/g-2.png.41a297bee162bdaf902b83195440dbde.png);
  background-size: contain;
  background-repeat: no-repeat;
}

7 minutes ago, bangank36 said:

Thank you so much! Worked perfectly. I'm grateful. ~ Jane

@SeeThroughPie I see on tablet, the title not center.