placeholder修改默认颜色

:-moz-placeholder { /* Mozilla Firefox 4 to 18 */      
    color: #f00;  
}

::-moz-placeholder { /* Mozilla Firefox 19+ */
    color: #f00;
}

input:-ms-input-placeholder,
textarea:-ms-input-placeholder {
    color: #f00;
}

input::-webkit-input-placeholder,
textarea::-webkit-input-placeholder {
    color: #f00;
}