CSS - 修改input - placeholder 和 readonly 的样式

::-webkit-input-placeholder { /* WebKit browsers */
color: #999999;
}
:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
color: #999999;
}
::-moz-placeholder { /* Mozilla Firefox 19+ */
color: #999999;
}
:-ms-input-placeholder { /* Internet Explorer 10+ */
color: #999999;
}

.mint-field-core[readonly] {
color: #999999;
}