I wanted to add a nice looking border and shadow to my WordPress images added within the post but did not want to add a plugin. Plugin has its own cost in terms of performance so I did not want to add a plugin for the sake of adding border and shadow to the images. Here is an extremely simple trick to add border and shadow only to your post images. If you change the theme, you may need to follow the same steps again but I think it is worth.
Login to your WordPress blog and go to Appearance > Customize.

Look for “Additional CSS” option and click on it

Add the following code in the box as shown in the image and click on “Save and Publish”.
/*change border color #C0C0C0 and shadow color #ccc to any color of your choice */
.post img {
border:1px solid #C0C0C0;
box-shadow: 10px 10px 5px #ccc;
-moz-box-shadow: 10px 10px 5px #ccc;
-webkit-box-shadow: 10px 10px 5px #ccc;
-khtml-box-shadow: 10px 10px 5px #ccc;
}

You are done.
Note: Depending on your theme, the featured image may or may not be affected by this css. If the featured image is affected and you don’t want the border and shadow, there is not a standard way to exclude the featured image. As the theme designers have coded featured image in different ways, you need to have a css programming skills in order to exclude featured image for your theme.
Hello Vishal,
Thank you so much, your post really helped save me time and it is always a problem to find the class selector; sometimes it is “wood for trees” as it is said.. 🙂
Thank you so much, it really helped me
Wow, This is what I was looking for to add shadows to my blog images. Very impressive and short tips. Thanks.
Nice thought, i am also add my site and its work for genesis theme . thanks for a grest tips
how to add border to each posts? can you please help me out here.
Hello Kiran,
You need to look at the theme or WordPress theme documentation to find the exact css class name used for the post and add a border property to that css class definition. Definition can be stored at the place mentioned in this blog post.
Regards
Vishal Monpara
Hi Vishal,
Amazing short and sweet post. I was just able to add awesome drop shadows in almost no time with provided code.
Though, have a small query, is there any way How to avoid the shadows for the feature image?