#browser,
#appcontent,
#tabbrowser-tabpanels {
  background: transparent !important;
}

#navigator-toolbox {
  /* see issue #426 */
  background: var(--zen-navigator-toolbox-background, transparent) !important;
  --inactive-titlebar-opacity: 1;
}

:root:not([inDOMFullscreen='true']):not([chromehidden~='location']):not([chromehidden~='toolbar']) {
  & #tabbrowser-tabpanels {
    padding-right: var(--zen-element-separation);
    padding-bottom: var(--zen-element-separation);

    #browser:has(#navigator-toolbox[zen-right-side="true"]) & {
      padding-right: 0;
      padding-left: var(--zen-element-separation);
    }
  }
}

:root:is([inDOMFullscreen='true'], [chromehidden~='location'], [chromehidden~='toolbar']) {
  #navigator-toolbox,
  #zen-sidebar-splitter {
    display: none;
  }
}

#browser {
  width: 100%;
}

:root:not([inDOMFullscreen='true']) #appcontent,
#sidebar-box {
  /** Sidebar is already hidden in full screen mode */
  border: none;
}

#zen-main-app-wrapper {
  background: var(--zen-main-browser-background);
}

#tabbrowser-tabbox {
  display: flex;
  flex-direction: row;
}

.titlebar-buttonbox-container {
  height: 100%;
}

:root:not([inDOMFullscreen='true']) #tabbrowser-tabbox {
  padding: 1px; /* To allow the web view's shadow to be visible */
}