Thumbnails album NextGen Gallery

Hello,
I’m using the Serene theme and have little problems with my album thumbnails on NextGen Gallery.
I have changed little things in the style sheet to have some big thumbnails inline but now those thumbnails are blur and I can’t put off the black border.
Here is my page : http://barbararyckewaert.com/photo/
All my image quality options are put on 100%.
That is my custom style sheet :

[ Moderator Note: Please post code or markup snippets between backticks or use the code button. ]

This stylesheet is provided to allow users the ability of overriding the default styles for all display types
*/

html > body .ngg-album {
    border: 0 solid #CCCCCC;
    display: inline-block !important;
    margin-bottom: 0px;
    padding: 15px;
}
.ngg-albumoverview {
    clear: both;
    display: inline-block!important;
    margin-top: 0;
text-align: left;
    width: 1000px;
}
.ngg-thumbnail {
    float: center;
    margin-right: 12px;
    border:0px;
}

.ngg-album-compactbox {
	background:transparent url(albumset.gif) no-repeat scroll 0%;
	height:300px;
	width:300px;
}

.ngg-album-compactbox .Thumb {
	border:0px;
	margin:0px !important;
	padding:0px !important;
	width:300px;
	height:300px;
}
.ngg-thumbnail img {
	background-color:#FFFFFF;
	border:1px solid #99CC99;
	margin:4px 0px 4px 5px;
	padding:4px;
	position:relative;
}

Thank you