chrome下input focus預設有個黃色的光影，如果不想要的話 可以在css樣式中 新增一下

      input：focus{

         outline:none;

     }

  就可以去掉了！

   我的樣式程式碼：

    input{

       border-radius:6px;
       border:1px solid #909090;
       -webkit-transition: box-shadow 0.30s ease-in-out;   //只讓box-shadow屬性做過渡效果！
       -moz-transition:  box-shadow 0.30s ease-in-out;      //firefox

    }

   input :focus{

     outline:none;
     border:#87C6F9 1px solid;
     box-shadow: 0 0 8px rgba(103, 166, 217, 1);

   }

 截圖如下：

.searchdemo {
display:inline-block;
position:relative;
height:27px;
margin:60px;
}
.searchdemo:hover {
-webkit-box-shadow:0 0 3px #999;
-moz-box-shadow:0 0 3px #999
}
.searchdemo .sinput {
float:left;
width:130px;
height:19px;
line-height:19px;
padding:3px 5px;
border:#A7A7A7 1px solid;
background:white;
color:#888;
font-size:12px;
-webkit-transition:.3s;
-moz-transition:.3s;
outline: none;
}
.searchdemo .sinput:focus {
width:200px;
}
.searchdemo .sbtn {
cursor:pointer;
height:27px;
font-size:12px;
float:left;
width:50px;
margin-left:-1px;
background:#eee;
display:inline-block;
padding:0 12px;
vertical-align:middle;
border:#A7A7A7 1px solid;
color:#666;
}
.searchdemo .sbtn:hover {
background:#ddd;
}

<form action="/index.php" method="get"><input type="text" name="s" /> <input type="submit" value="搜尋" /></form>