Firefox css -moz-appearance how to change background?

Question

css

I fix the layout in firefox, it was made up under webkit. Customized radio through appearance and through the background there is a picture. I can not understand where the background of the element comes from, I tried the css properties unsuccessfully. As a result, without checked, the element has a white background:

When checked, black filling appears, iterating over properties does not help to find the cause.
I went to Google, I didn’t find anything, thanks for the help) The pictures are transparent.

.class {
    height: 50px;
    margin: 7px 0px 0px 1px!important;
    width: 228px;
    background-color: #C5C5C5;
    background: url(/img/1b.png) 0 0 no-repeat;
    outline: none;
    cursor: pointer;
    border-radius: 50px;
    transition: all .5s;
}
.class:checked {
  margin: 7px 0px 0px 1px !important;
  background-color: rgb(39, 109, 11);
  background: url(/img/1a.png) 0 0 no-repeat;
  outline: none;
  transition: all .5s;
  }
input {
-webkit-appearance: textfield;
-moz-appearance:    textfield;
appearance:         textfield;
-webkit-rtl-ordering: logical;
user-select: text;
cursor: auto;
padding: 1px;
border-width: 0px;
border-style: inset;
border-color: initial;
border-image: initial;
outline: none;
}

PS Please do not scold me for the code, I did not write it)