CSS doesn't apply

I'm editing the css for a module of prestashop but all the changes I set don't appear on my site. I tried to delete the CSS stylesheet to be sure i was working on the right CSS and all the properties were gone, so I tried to comment one by one all the strings to find out the problem but when I uploaded it the properties were there.

Site: backlabel.com look at the newsletter block on the Footer, precisely at the <button> where I tried to remove the position:absolute

the CSS stylesheet

/* Block newsletter */

 #columns #newsletter_block_left .form-group {
   margin-bottom: 0;
 }

 #columns #newsletter_block_left .form-group .form-control {
   max-width: 222px;
   display: inline-block;
   margin-right: 6px;
 }

 @media (min-width: 768px) and (max-width: 1199px) {
   #columns #newsletter_block_left .form-group .form-control {
     margin-bottom: 10px;
     margin-right: 0;
   }
 }

 #columns #newsletter_block_left .success_inline, #columns      #newsletter_block_left .warning_inline {
   text-align: left;
   padding: 1px 0 0 0;
   margin-bottom: -19px;
 }

 #columns #newsletter_block_left .success_inline {
   color: #418B19;
 }

 #columns #newsletter_block_left .warning_inline {
   color: #f13340;
 }

 /* Block newsletter footer */ 
 #footer #newsletter_block_left {
   -webkit-transition: all 0.5s ease-in-out 0s;
   transition: all 0.5s ease-in-out 0s;
 }

 #footer #newsletter_block_left form {
   position: relative;
   margin-top: 35px;
 }

 #footer #newsletter_block_left .form-group {
   margin-bottom: 0;
   margin-top: 20px;
 }

 #footer #newsletter_block_left .form-group .form-control {
   height: 40px;
   line-height: 30px;
   width: 100%;
   padding: 5px 40px 5px 15px;
   display: inline-block;
   background-color: transparent;
   border: 1px solid #adadad;
 }

 #footer #newsletter_block_left .form-group .button-small {
   color: #999999;
   font-size: 17px;
   border: 0;
   background: transparent;
   /* HERE IS WHERE I REMOVED THE POSITION:ABSOLUTE */
   right: 0px;
   top: 0px;
   padding: 8px 10px;
 }

 .rtl #footer #newsletter_block_left .form-group .button-small {
   left: 0px;
   right: auto;
 }

 #footer #newsletter_block_left .form-group .button-small .icon {
   position: relative;
   top: -1px;
 }

 #footer #newsletter_block_left .form-group .button-small:hover {
   color: #fff;
 }

 #footer #newsletter_block_left .warning_inline {
   display: block;
   color: #f13340;
   font-size: 13px;
   line-height: 26px;
   clear: both;
 }

 @media (min-width: 1200px) {
   #footer #newsletter_block_left .warning_inline {
     display: inline-block;
     position: relative;
     top: -35px;
     margin-bottom: -35px;
     left: 15px;
     clear: none;
   }
 }

 #footer #newsletter_block_left.active {
   right: 0;
 }

 #footer #newsletter_block_left .form-group.form-error input, #footer  
 #newsletter_block_left .form-group.form-error textarea {
   background: none;
   background-color: #fff1f2;
 }