broken inlined button, FF

dabblet.css

/* broken inlined button, FF */
.btn {
	all: initial;
	background: red;
}

/* fix for 140562 https://bugzilla.mozilla.org/show_bug.cgi?id=140562 */
.btn::-moz-focus-inner { all: initial; }

.btn.ib { display: inline-block; }

dabblet.html

<a class="btn">Button</a>
<button class="btn">Button</button>  
<button class="btn ib">Button</button>

settings.json

{"view":"split","fontsize":"100","seethrough":"","prefixfree":"1","page":"all"}