Firefox, since version 23, natively supports the <input type="range"> element, but I couldn’t figure out how to remove the dotted outline. The following CSS has no effect:
input[type='range'], 
input[type='range']:focus, 
input[type='range']:active, 
input[type='range']::-moz-focus-inner, 
input[type='range']:-moz-focusring {
    border: 0;
    outline: none;
}
Does anyone have any idea how to fix this issue in Firefox?
Example: https://jsfiddle.net/pF37g/