#main-window:not([drawtitle="true"]):not([inFullscreen="true"])

#nav-bar {

    margin-left : 30px;  /* leftTop drag area */

    border-right: 140px solid var(--toolbar-bgcolor);

:root[sizemode="maximized"] #nav-bar {

    margin-top: -16px !important;   /* Top drag area */

    margin-left : 0px !important;  /* hidden leftTop drag area in Fullscreen mode*/

    border-right: 140px solid var(--toolbar-bgcolor);

:root[privatebrowsingmode="temporary"] #nav-bar {

    border-right: 180px solid var(--toolbar-bgcolor) !important;

/* move down to hidden titlebar */

#titlebar {

    margin-bottom: -31px !important;

/* move down 3 button on rightTop */

.titlebar-buttonbox-container {

  margin-bottom: 6px !important;

:root[sizemode="maximized"] .titlebar-buttonbox-container {

  margin-bottom: 6px !important;

/* move down private icon */

.private-browsing-indicator {

  margin-bottom: -8px !important;

:root[sizemode="maximized"] .private-browsing-indicator {

  margin-bottom: -18px !important;

/* hidden horizontal tabbar on top */

#tabbrowser-tabs[orient="horizontal"] {

    visibility: collapse !important;

#sidebar-box[sidebarcommand="_0ad88674-2b41-4cfb-99e3-e206c74a0076_-sidebar-action"]

sidebarheader {

    visibility: collapse !important;

如果顶部或者最大化、最小化、关闭位置显示不贴合。可调整

:root[sizemode="maximized"] #nav-bar {

    margin-top: -16px !important;   /* Top drag area */

"-16px"参数

/* move down 3 button on rightTop */

.titlebar-buttonbox-container {

margin-bottom: 6px !important;

:root[sizemode="maximized"] .titlebar-buttonbox-container {

margin-bottom: 6px !important;

“两个6px"参数，其它位置同理