CSS样式适用于Chrome，但不适用于Firefox

Question

In this case, i'm using bootstrap and added my own class for custom styling. my custom style works on Chrome but not in Mozilla.. here is the example:

element:

<input class="form-control en-input-label" id="source" name="source" value="Personal Contact" aria-required="true" aria-invalid="false" readonly />

on Chrome, it looks like this:

but on Firefox, the style doesn't really apply, and it looks like this:

here is the css comparison from dev tools..

Chrome:

but, Firefox can't read the en-input-label class and go with the default class instead.

can anyone explain what happens? why chrome is able to read the en-input-label but Firefox can't ?

EDIT:

Here are css for en-input-label

.form-control.en-input-label, .form-control.en-input-label:read-only {
    border-left: none;
    border-top: none;
    border-right: none;
    border-color: #e6e6e6;
    padding: 0px;
    display: inline-table;
    height: 30px;
    line-height: 30px;
    box-shadow: none;
    -webkit-box-shadow: none;
    margin-bottom: 0px;
    background: transparent;
    font-size: 12px;
    color: #777;
    font-weight: 500;
}

any other css related to the elems is form-control from bootstrap:

.form-control {
    display: block;
    width: 100%;
    height: 34px;
    padding: 6px 12px;
    font-size: 14px;
    line-height: 1.42857143;
    color: #555;
    background-color: #fff;
    background-image: none;
    border: 1px solid #ccc;
    border-radius: 0;
    -webkit-box-shadow: inset 0 1px 1px rgba(0,0,0,0.075);
    box-shadow: inset 0 1px 1px rgba(0,0,0,0.075);
    -webkit-transition: border-color ease-in-out .15s, -webkit-box-shadow ease-in-out .15s;
    -o-transition: border-color ease-in-out .15s, box-shadow ease-in-out .15s;
     transition: border-color ease-in-out .15s, box-shadow ease-in-out .15s;
}

Answer 1

原因是Firefox需要供应商前缀 ，因此：

.form-control.en-input-label:-moz-read-only {