mobile-config-firefox/chrome/dark_checkboxes_and_radios.css

/* Change the appearance of natively styled widgets including radios, checkboxes, buttons and expender "dropdown" arrows */
/* Their background will be transparent instead of white so they will appear fitting to whatever is on the background */
/* As such, this might cause a small issue if the background happens to be same color as the border of these buttons or the checkbox-image */

/* In short, these native widgets will be dark on dark theme and light on light theme */

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");

#editBMPanel_tagsSelector > richlistitem > image,
radio > .radio-check,
checkbox > .checkbox-check{
  -moz-appearance: none !important;
  border: 1px solid graytext;
  border-radius: 2px;
  height: 1.3em;
  width: 1.3em;
  padding: 1px;
}

#editBMPanel_tagsSelector > richlistitem > image{
  background-color: var(--toolbar-bgcolor,rgb(50,50,52)) !important;
  margin: 1px !important;
  border-color: graytext !important;
  border-radius: 2px !important;
}

#editBMPanel_tagsSelector > richlistitem:not([disabled]):hover > image,
radio:not([disabled]):hover > .radio-check,
checkbox:not([disabled]):hover > .checkbox-check{ border-color: highlight !important; }

radio > .radio-check{ padding: 0; border-radius: 20px }

#editBMPanel_tagsSelector > richlistitem[checked] > image,
radio[selected] > .radio-check,
checkbox[checked] > .checkbox-check{
  list-style-image: url("chrome://global/skin/icons/check.svg");
  -moz-context-properties: fill;
  fill: highlight;
}

radio[selected] > .radio-check{ list-style-image: url("chrome://global/skin/in-content/radio.svg"); }

#editBMPanel_tagsSelector > richlistitem[disabled] > image,
radio[disabled] > .radio-check,
checkbox[disabled] > .checkbox-check{ fill: graytext !important; }

/*Buttons*/
/* This only applies to natively-ish styled buttons, not the buttons in toolbars */

button{
  -moz-appearance: none !important;
  color: inherit !important;
	background-color: rgba(127,127,127,0.1) !important;
  border: 1px solid graytext;
}

button[disabled]{ opacity: 0.8 }


button:not([disabled]):hover{ border-color: highlight; background-color: rgba(0,0,0,0.1) !important; box-shadow: inset 0 0 2px highlight }
button:not([disabled]):active{ box-shadow: inset 0 0 3px 0px black }
button.searchbar-engine-one-off-item,
.panel-footer > button{ border-width: 1px 0 0 0; }

button.panel-button{ padding: 2px 2px 1px 2px !important; }

#customization-done-button{ background-color: #0a84ff !important; }
#customization-done-button:hover{ background-color: #0a64df !important; }