input img 等一些表单元素之间有默认的间隙可能会导致超出父盒子的宽需要浮动间隙就没了

.search input {
width: 450px;
height: 32px;
border: 2px solid #b61d1d;
padding-left:4px;
color:#666;
font:14px/32px "Microsoft YaHei";
float: left;
}
.search button {
width: 80px;
height: 36px;
background-color: #b61d1d;
float: left;
}