Remove shadow around image thumbails and on post pages

Hello,

Thanks for a wonderful theme.

I would like to remove the light grey shadow around the thumbnails for my posts and also the shadow around the whole text block on the post pages themselves. I saw that someone else on here used the code:

#primary {
background: #fff;
-webkit-box-shadow: none!important;
-moz-box-shadow: none!important;
-ms-box-shadow: none!important;
box-shadow: none!important;
margin: 0 auto;
padding: 0 0 30px 0;
}

I have edited this in my css file but nothing has changed. How can I remove the shadows?

Many thanks!