Firefox Proton macOS Close Tab Left

userChrome.css

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

.tabbrowser-tab .tab-throbber,
.tabbrowser-tab .tab-icon-image,
.tabbrowser-tab .tab-sharing-icon-overlay,
.tabbrowser-tab .tab-icon-overlay,
.tabbrowser-tab .tab-label-container,
.tabbrowser-tab .tab-icon-sound {
  -moz-box-ordinal-group: 2 !important;
}
.tabbrowser-tab .tab-close-button {
  margin-left: -5.5px !important;
  margin-right: 3px !important;
}
.tabbrowser-tab:not([pinned="true"]):hover .tab-close-button {
  display: -moz-box !important;
}
.tabbrowser-tab:not([pinned="true"]):hover .tab-icon-image,
.tabbrowser-tab:not([pinned="true"]):hover .tab-throbber {
  display: none;
}
.tab-close-button {
  display: none;
}

thanks m8, this is what I was looking for. this is how it looks my Linux now thanks to you 😛:

@G3NSVRV, your Linux/theme looks nice! Which distro is it?

@biosmanager, it seems we could even simplify with the following, from "Close tab" button on left?:

.tabbrowser-tab .tab-close-button {
  -moz-box-ordinal-group: 0 !important;
}

@G3NSVRV, your Linux/theme looks nice! Which distro is it?

Garuda KDE + firefox-appmenu