ul.thumb { float: left; list-style: none; margin: 0; padding: 10px; width: 450px; } ul.thumb li { margin: 0; padding: 5px; float: left; position: relative; width: 125px; height: 125px; } ul.thumb li img { width: 100px; height: 100px; -ms-interpolation-mode: bicubic; border: 1px solid #ddd; padding: 5px; background: #f0f0f0; position: absolute; left: 0; top: 0; } ul.thumb li img.hover { background:url(https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjxhX_4nJskHemVvtOfMRQUBPg7ODn5ujLEfZvthgZ2iqxLVABbiB1ovFAOzANSj_BHJ1nbXB2QrpAL58pBXZ3bqulXCeeqiABoqPPv1_OUObcM0K9QIuE1DlnihueLkbN1lBfJhdhcbD0S/) no-repeat center center; border: none; }