去除input[type=number]的默認樣式

input[type=number] {
    -moz-appearance:textfield;
}
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

參考地址：

僞元素表單控件默認樣式重置與自定義大全

http://www.zhangxinxu.com/wordpress/2013/06/%E4%BC%AA%E5%85%83%E7%B4%A0-%E8%A1%A8%E5%8D%95%E6%A0%B7%E5%BC%8F-pseudo-elements-style-form-controls/