You can achieve this nice looking effect with simple modification of the global.css styles file located in your theme directory. If you use some non-default theme, you can also achieve this effect with this easy in use modification. Just use styles for your container block. Wondering how this effect looks like in real store? just check our website demo page: prestashop demo

How to add shadow effect?

As I said it will be necessary to modify your main css styles file. In default theme this file is located in directory: /themes/default/css/ and the file name is global.css. Open this file and add somewhere this simple code:

#page {
box-shadow: 0px 0px 20px #888;
padding: 10px;
background: #FFF;
}

that's all. Now your container block will have nice looking shadow effect.

Don't know how to edit global.css file?

If you aren't familiar with coding and editing prestashop core / theme files i've got easiest solution. Just download free html block module. Install it in your prestashop and open configuration page. From left hand side block select "header", and to the right hand side block insert this simple code:

<style>
#page {
box-shadow: 0px 0px 20px #888;
padding: 10px;
background: #FFF;
}
</style>

After that it's time to save changes. That's all!