input的placeholder颜色修改

input[type=text]::-webkit-input-placeholder { /* WebKit browsers /
color: #999;
}
input[type=text]:-moz-placeholder { / Mozilla Firefox 4 to 18 /
color: #999;
}
input[type=text]::-moz-placeholder { / Mozilla Firefox 19+ /
color: #999;
}
input[type=text]:-ms-input-placeholder { / Internet Explorer 10+ */
color: #999;
}