background:#f2f2f2  center repeat;
border-bottom: 1px solid #e9e9e9;
border-top: 1px solid #f9f9f9;
2.突出效果
background:#f2f2f2  center repeat;
border-top: 1px solid #e9e9e9;
border-bottom: 1px solid #f9f9f9;