win95 style firefox

userChrome.css

.tabbrowser-tab:not([pinned]) {
  min-width: 1px !important;
}

.tab-close-button {
  display: none;
}

.tab-background {
  margin-block: 0 !important;
  box-shadow: none !important;
  background: #B3B3B3 !important;
  outline: none !important;
  border-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAAAAACoBHk5AAAAGElEQVR4AWN4CQQMDC83b66Fk7W1QBIMAOQuC52e5EQ7AAAAAElFTkSuQmCC') 2 / 2px !important;
}

.tab-background[selected] {
  border-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAAAAACoBHk5AAAAFklEQVR4AWOAgtra2pdAcvNmOPkSCAB4VguduIWGtgAAAABJRU5ErkJggg==') 2 / 2px !important;
}

#tabbrowser-tabs[haspinnedtabs]:not([positionpinnedtabs]) > #tabbrowser-arrowscrollbox > .tabbrowser-tab[first-visible-unpinned-tab] {
  margin-inline-start: 0px !important;
}

.tabbrowser-tab {
  padding: 0 !important;
  margin-inline-start: 0 !important;
}


toolbox toolbarbutton {
  background: #B3B3B3 !important;
  margin-inline: 0px !important;
}

toolbox toolbarbutton:not([disabled="true"]):hover {
  border-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAAAAACoBHk5AAAAGElEQVR4AWN4CQQMDC83b66Fk7W1QBIMAOQuC52e5EQ7AAAAAElFTkSuQmCC') 2 / 2px !important;
}

#personal-toolbar-empty-description, toolbarbutton.bookmark-item:not(.subviewbutton) {
  margin: 0px !important;
  padding: 3px 6px !important;
}

toolbox toolbarbutton > * {
  background: transparent !important;
}

toolbox toolbarbutton:not([disabled="true"]):active {
  border-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAAAAACoBHk5AAAAFklEQVR4AWOAgtra2pdAcvNmOPkSCAB4VguduIWGtgAAAABJRU5ErkJggg==') 2 / 2px !important;
}

#urlbar-background {
  border-radius: 0px !important;
  border: 1px solid #7d7d7d !important;
}

#urlbar-input-container {
  border-radius: 0px !important;
}

#PersonalToolbar {
  padding-inline: 0px !important;
}


#navigator-toolbox {
  border-bottom: none !important;
}

#TabsToolbar {
  --toolbarbutton-inner-padding: 0px !important;
}

#nav-bar:not([tabs-hidden="true"]) {
  box-shadow: none !important;
}

#TabsToolbar toolbarbutton {
  margin: 0 0 0 !important;
  min-width: 30px !important;
  min-height: 30px !important;
}

#TabsToolbar tab {
  height: 30px !important;
}

toolbar .toolbaritem-combined-buttons {
  margin: 0 !important;
}

toolbaritem {
  padding-inline-end: 0px !important;
  padding-inline-start: 0px !important;
}
toolbarbutton {
  padding-inline-end: 3px !important;
  padding-inline-start: 3px !important;
}

#nav-bar-customization-target toolbarbutton {
  min-height: 34px !important;
}

#tabbrowser-tabs:not([overflow="true"])[using-closing-tabs-spacer] ~ #alltabs-button {
  display: none !important;
}

/* hide webrtc */
#webrtcIndicator {
  display: none;
}

.tab-icon-overlay[soundplaying="true"], .tab-icon-overlay[soundplaying=""], .tab-icon-overlay[sharing="microphone"], .tab-icon-overlay {
  pointer-events: none !important;
}

.tab-icon-stack[activemedia-blocked] > :not(.tab-icon-overlay) {
  opacity: 1 !important;
}

.tab-icon-overlay[indicator-replaces-favicon][activemedia-blocked] {
  display: none;
}

#alltabs-button {
  display: none;
}

:root {
  --tab-min-height: 0px !important;
}

#nav-bar {
  border-top: none !important;
}

#tabbrowser-tabs {
  --tab-min-width: 1px !important;
}

.tabbrowser-tab:not([pinned]) .tab-content {
  padding: 0 min(var(--tab-inline-padding), 100%) !important;
}

#nav-bar-customization-target toolbarbutton {
  min-height: 0px !important;
}

.tab-audio-button {
  display: none !important;
}