diff --git a/src/gtk-3.0/assets.svg b/src/gtk-3.0/assets.svg
index 330ddc7..e51be13 100644
--- a/src/gtk-3.0/assets.svg
+++ b/src/gtk-3.0/assets.svg
@@ -522,6 +522,50 @@
        y1="31.36219"
        x2="25"
        y2="45.36219" />
+    <linearGradient
+       inkscape:collect="always"
+       xlink:href="#header_button_img_dark"
+       id="linearGradient1971"
+       gradientUnits="userSpaceOnUse"
+       gradientTransform="matrix(1.0590966,0,0,1.0913439,-81.434726,60.086499)"
+       x1="534.82819"
+       y1="-248.98138"
+       x2="534.82819"
+       y2="-274.63782" />
+    <linearGradient
+       id="header_button_img_dark"
+       osb:paint="gradient">
+      <stop
+         id="stop1959"
+         offset="0"
+         style="stop-color:#636363;stop-opacity:1" />
+      <stop
+         id="stop1961"
+         offset="1"
+         style="stop-color:#696969;stop-opacity:1" />
+    </linearGradient>
+    <linearGradient
+       inkscape:collect="always"
+       xlink:href="#header_button_img"
+       id="linearGradient1969"
+       gradientUnits="userSpaceOnUse"
+       gradientTransform="matrix(1.0590966,0,0,1.0913439,-81.434726,25.086497)"
+       x1="534.82819"
+       y1="-248.98138"
+       x2="534.82819"
+       y2="-274.63782" />
+    <linearGradient
+       id="header_button_img"
+       osb:paint="gradient">
+      <stop
+         style="stop-color:#f1f1f1;stop-opacity:1"
+         offset="0"
+         id="stop1945" />
+      <stop
+         style="stop-color:#fefefe;stop-opacity:1"
+         offset="1"
+         id="stop1947" />
+    </linearGradient>
   </defs>
   <sodipodi:namedview
      id="base"
@@ -530,17 +574,17 @@
      borderopacity="1.0"
      inkscape:pageopacity="0.0"
      inkscape:pageshadow="2"
-     inkscape:zoom="7.3049648"
-     inkscape:cx="405.22841"
-     inkscape:cy="203.75753"
+     inkscape:zoom="2.5826951"
+     inkscape:cx="407.9448"
+     inkscape:cy="134.69986"
      inkscape:document-units="px"
      inkscape:current-layer="layer1"
      showgrid="true"
      showborder="true"
      inkscape:window-width="1920"
-     inkscape:window-height="1046"
+     inkscape:window-height="1025"
      inkscape:window-x="0"
-     inkscape:window-y="34"
+     inkscape:window-y="29"
      inkscape:window-maximized="1"
      inkscape:snap-nodes="false"
      inkscape:snap-bbox="true"
@@ -5459,5 +5503,55 @@
          style="opacity:0.5;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.39687499;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
          inkscape:connector-curvature="0" />
     </g>
+    <g
+       style="display:inline"
+       id="setting"
+       inkscape:label="#g1979"
+       transform="translate(-90,118)">
+      <rect
+         y="-274.63782"
+         x="464"
+         height="28"
+         width="42"
+         id="rect1943"
+         style="opacity:1;fill:url(#linearGradient1969);fill-opacity:1;fill-rule:evenodd;stroke:none;stroke-width:2.51955914;stroke-linecap:square;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:0.19607843;paint-order:stroke markers fill" />
+      <path
+         inkscape:label="#path17"
+         d="m 492.9504,-261.526 c -0.0253,-0.22491 -0.28755,-0.39393 -0.51431,-0.39393 -0.73315,0 -1.38373,-0.43047 -1.65657,-1.09622 -0.27874,-0.68189 -0.099,-1.47712 0.44739,-1.97832 0.17199,-0.15722 0.19289,-0.42042 0.0486,-0.60324 -0.37524,-0.4765 -0.80173,-0.90691 -1.26741,-1.27994 -0.18235,-0.14634 -0.44989,-0.12598 -0.60801,0.0491 -0.47686,0.52811 -1.33343,0.72439 -1.99532,0.44821 -0.6888,-0.28974 -1.12315,-0.98769 -1.08065,-1.73691 0.014,-0.23533 -0.158,-0.43994 -0.39262,-0.46727 -0.59759,-0.0691 -1.20043,-0.0713 -1.79981,-0.005 -0.23194,0.0256 -0.40393,0.22539 -0.39613,0.45775 0.026,0.74183 -0.41352,1.42758 -1.09548,1.70691 -0.65397,0.26711 -1.50452,0.0725 -1.98043,-0.4509 -0.15729,-0.17241 -0.42048,-0.1936 -0.60373,-0.0508 -0.47948,0.37618 -0.91556,0.80695 -1.29425,1.27953 -0.1477,0.18371 -0.12597,0.45 0.0477,0.60806 0.55682,0.50423 0.73661,1.30637 0.44734,1.99612 -0.27618,0.65759 -0.95903,1.0814 -1.74076,1.0814 -0.25367,-0.008 -0.43435,0.1621 -0.4621,0.39273 -0.0704,0.60104 -0.0712,1.21345 -0.004,1.81937 0.0251,0.22587 0.29535,0.39339 0.52461,0.39339 0.69666,-0.0178 1.36552,0.41351 1.6461,1.09629 0.27968,0.68188 0.0999,1.47663 -0.44734,1.97825 -0.17116,0.15723 -0.19288,0.42 -0.0486,0.60283 0.37173,0.47346 0.79828,0.90429 1.26562,1.28042 0.1833,0.1477 0.45001,0.12686 0.60891,-0.0482 0.47864,-0.52942 1.33515,-0.72534 1.99442,-0.44864 0.69053,0.28885 1.12488,0.98675 1.08238,1.73638 -0.0138,0.23545 0.15895,0.44042 0.39262,0.46733 0.3057,0.0357 0.61325,0.0535 0.92164,0.0535 0.29272,0 0.5855,-0.0161 0.87823,-0.0486 0.232,-0.0256 0.40387,-0.22539 0.39608,-0.45816 -0.0268,-0.74142 0.41351,-1.42717 1.09457,-1.70602 0.65838,-0.26891 1.50536,-0.0721 1.98133,0.45078 0.15818,0.17205 0.41953,0.19282 0.60379,0.0505 0.47859,-0.37529 0.91377,-0.80571 1.29425,-1.27958 0.14764,-0.18331 0.12681,-0.45001 -0.0478,-0.60801 -0.55681,-0.50424 -0.7375,-1.30649 -0.44823,-1.99576 0.27195,-0.64884 0.92944,-1.0845 1.63664,-1.0845 l 0.0989,0.002 c 0.22938,0.0187 0.44043,-0.15806 0.46823,-0.3922 0.0705,-0.60157 0.0713,-1.21345 0.003,-1.81936 z m -7.93728,3.57372 c -1.47155,0 -2.66852,-1.19695 -2.66852,-2.66847 0,-1.47146 1.19697,-2.66848 2.66852,-2.66848 1.47148,0 2.66846,1.19702 2.66846,2.66848 0,1.47152 -1.19698,2.66847 -2.66846,2.66847 z"
+         id="setting-img"
+         inkscape:connector-curvature="0"
+         style="clip-rule:evenodd;fill:#575757;fill-opacity:1;fill-rule:evenodd;stroke-width:0.07842982" />
+    </g>
+    <g
+       style="display:inline"
+       id="setting-dark"
+       inkscape:label="#g1983"
+       transform="translate(-90,118)">
+      <rect
+         style="opacity:1;fill:url(#linearGradient1971);fill-opacity:1;fill-rule:evenodd;stroke:none;stroke-width:2.51955914;stroke-linecap:square;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:0.19607843;paint-order:stroke markers fill"
+         id="rect1953"
+         width="42"
+         height="28"
+         x="464"
+         y="-239.63782" />
+      <path
+         style="clip-rule:evenodd;fill:#fdfdfd;fill-opacity:1;fill-rule:evenodd;stroke-width:0.07842982"
+         inkscape:connector-curvature="0"
+         id="path1955"
+         d="m 492.9504,-226.526 c -0.0253,-0.22491 -0.28755,-0.39393 -0.51431,-0.39393 -0.73315,0 -1.38373,-0.43047 -1.65657,-1.09622 -0.27874,-0.68189 -0.099,-1.47712 0.44739,-1.97832 0.17199,-0.15722 0.19289,-0.42042 0.0486,-0.60324 -0.37524,-0.4765 -0.80173,-0.90691 -1.26741,-1.27994 -0.18235,-0.14634 -0.44989,-0.12598 -0.60801,0.0491 -0.47686,0.52811 -1.33343,0.72439 -1.99532,0.44821 -0.6888,-0.28974 -1.12315,-0.98769 -1.08065,-1.73691 0.014,-0.23533 -0.158,-0.43994 -0.39262,-0.46727 -0.59759,-0.0691 -1.20043,-0.0713 -1.79981,-0.005 -0.23194,0.0256 -0.40393,0.22539 -0.39613,0.45775 0.026,0.74183 -0.41352,1.42758 -1.09548,1.70691 -0.65397,0.26711 -1.50452,0.0725 -1.98043,-0.4509 -0.15729,-0.17241 -0.42048,-0.1936 -0.60373,-0.0508 -0.47948,0.37618 -0.91556,0.80695 -1.29425,1.27953 -0.1477,0.18371 -0.12597,0.45 0.0477,0.60806 0.55682,0.50423 0.73661,1.30637 0.44734,1.99612 -0.27618,0.65759 -0.95903,1.0814 -1.74076,1.0814 -0.25367,-0.008 -0.43435,0.1621 -0.4621,0.39273 -0.0704,0.60104 -0.0712,1.21345 -0.004,1.81937 0.0251,0.22587 0.29535,0.39339 0.52461,0.39339 0.69666,-0.0178 1.36552,0.41351 1.6461,1.09629 0.27968,0.68188 0.0999,1.47663 -0.44734,1.97825 -0.17116,0.15723 -0.19288,0.42 -0.0486,0.60283 0.37173,0.47346 0.79828,0.90429 1.26562,1.28042 0.1833,0.1477 0.45001,0.12686 0.60891,-0.0482 0.47864,-0.52942 1.33515,-0.72534 1.99442,-0.44864 0.69053,0.28885 1.12488,0.98675 1.08238,1.73638 -0.0138,0.23545 0.15895,0.44042 0.39262,0.46733 0.3057,0.0357 0.61325,0.0535 0.92164,0.0535 0.29272,0 0.5855,-0.0161 0.87823,-0.0486 0.232,-0.0256 0.40387,-0.22539 0.39608,-0.45816 -0.0268,-0.74142 0.41351,-1.42717 1.09457,-1.70602 0.65838,-0.26891 1.50536,-0.0721 1.98133,0.45078 0.15818,0.17205 0.41953,0.19282 0.60379,0.0505 0.47859,-0.37529 0.91377,-0.80571 1.29425,-1.27958 0.14764,-0.18331 0.12681,-0.45001 -0.0478,-0.60801 -0.55681,-0.50424 -0.7375,-1.30649 -0.44823,-1.99576 0.27195,-0.64884 0.92944,-1.0845 1.63664,-1.0845 l 0.0989,0.002 c 0.22938,0.0187 0.44043,-0.15806 0.46823,-0.3922 0.0705,-0.60157 0.0713,-1.21345 0.003,-1.81936 z m -7.93728,3.57372 c -1.47155,0 -2.66852,-1.19695 -2.66852,-2.66847 0,-1.47146 1.19697,-2.66848 2.66852,-2.66848 1.47148,0 2.66846,1.19702 2.66846,2.66848 0,1.47152 -1.19698,2.66847 -2.66846,2.66847 z"
+         inkscape:label="#path17" />
+    </g>
+    <path
+       inkscape:label="#path17"
+       d="m 451.93727,-143.52601 c -0.0253,-0.22491 -0.28755,-0.39393 -0.5143,-0.39393 -0.73316,0 -1.38373,-0.43047 -1.65658,-1.09622 -0.27873,-0.68189 -0.099,-1.47712 0.4474,-1.97832 0.17199,-0.15722 0.19288,-0.42042 0.0486,-0.60324 -0.37523,-0.4765 -0.80173,-0.90691 -1.26741,-1.27994 -0.18234,-0.14634 -0.44988,-0.12598 -0.608,0.0491 -0.47686,0.52811 -1.33344,0.72439 -1.99532,0.44821 -0.6888,-0.28974 -1.12315,-0.98769 -1.08066,-1.73691 0.014,-0.23533 -0.15799,-0.43994 -0.39261,-0.46727 -0.5976,-0.0691 -1.20044,-0.0713 -1.79982,-0.005 -0.23194,0.0256 -0.40393,0.22539 -0.39612,0.45775 0.026,0.74183 -0.41352,1.42758 -1.09549,1.70691 -0.65397,0.26711 -1.50452,0.0725 -1.98043,-0.4509 -0.15729,-0.17241 -0.42048,-0.1936 -0.60373,-0.0508 -0.47948,0.37618 -0.91555,0.80695 -1.29424,1.27953 -0.14771,0.18371 -0.12598,0.45 0.0477,0.60806 0.55683,0.50423 0.73662,1.30637 0.44734,1.99612 -0.27618,0.65759 -0.95903,1.0814 -1.74075,1.0814 -0.25367,-0.008 -0.43435,0.1621 -0.46211,0.39273 -0.0704,0.60104 -0.0712,1.21345 -0.004,1.81937 0.0251,0.22587 0.29536,0.39339 0.52461,0.39339 0.69666,-0.0178 1.36553,0.41351 1.64611,1.09629 0.27968,0.68188 0.0999,1.47663 -0.44734,1.97825 -0.17117,0.15723 -0.19288,0.42 -0.0486,0.60283 0.37173,0.47346 0.79827,0.90429 1.26562,1.28042 0.18329,0.1477 0.45,0.12686 0.6089,-0.0482 0.47864,-0.52942 1.33515,-0.72534 1.99442,-0.44864 0.69054,0.28885 1.12489,0.98675 1.08238,1.73638 -0.0138,0.23545 0.15895,0.44042 0.39263,0.46733 0.3057,0.0357 0.61325,0.0535 0.92163,0.0535 0.29273,0 0.58551,-0.0161 0.87824,-0.0486 0.23199,-0.0256 0.40386,-0.22539 0.39607,-0.45816 -0.0268,-0.74142 0.41352,-1.42717 1.09458,-1.70602 0.65837,-0.26891 1.50536,-0.0721 1.98133,0.45078 0.15817,0.17205 0.41952,0.19282 0.60379,0.0505 0.47858,-0.37529 0.91377,-0.80571 1.29425,-1.27958 0.14763,-0.18331 0.12681,-0.45001 -0.0478,-0.60801 -0.55681,-0.50424 -0.7375,-1.30649 -0.44823,-1.99576 0.27195,-0.64884 0.92944,-1.0845 1.63663,-1.0845 l 0.0989,0.002 c 0.22938,0.0187 0.44043,-0.15806 0.46823,-0.3922 0.0705,-0.60157 0.0713,-1.21345 0.003,-1.81936 z M 444,-139.95229 c -1.47155,0 -2.66853,-1.19695 -2.66853,-2.66847 0,-1.47146 1.19698,-2.66848 2.66853,-2.66848 1.47147,0 2.66845,1.19702 2.66845,2.66848 0,1.47152 -1.19698,2.66847 -2.66845,2.66847 z"
+       id="setting-icon"
+       inkscape:connector-curvature="0"
+       style="clip-rule:evenodd;display:inline;fill:#fdfdfd;fill-opacity:1;fill-rule:evenodd;stroke-width:0.07842982" />
+    <path
+       style="clip-rule:evenodd;display:inline;fill:#575757;fill-opacity:1;fill-rule:evenodd;stroke-width:0.07842982"
+       inkscape:connector-curvature="0"
+       id="setting-icon-dark"
+       d="m 451.93727,-108.52601 c -0.0253,-0.22491 -0.28755,-0.39393 -0.5143,-0.39393 -0.73316,0 -1.38373,-0.43047 -1.65658,-1.09622 -0.27873,-0.68189 -0.099,-1.47712 0.4474,-1.97832 0.17199,-0.15722 0.19288,-0.42042 0.0486,-0.60324 -0.37523,-0.4765 -0.80173,-0.90691 -1.26741,-1.27994 -0.18234,-0.14634 -0.44988,-0.12598 -0.608,0.0491 -0.47686,0.52811 -1.33344,0.72439 -1.99532,0.44821 -0.6888,-0.28974 -1.12315,-0.98769 -1.08066,-1.73691 0.014,-0.23533 -0.15799,-0.43994 -0.39261,-0.46727 -0.5976,-0.0691 -1.20044,-0.0713 -1.79982,-0.005 -0.23194,0.0256 -0.40393,0.22539 -0.39612,0.45775 0.026,0.74183 -0.41352,1.42758 -1.09549,1.70691 -0.65397,0.26711 -1.50452,0.0725 -1.98043,-0.4509 -0.15729,-0.17241 -0.42048,-0.1936 -0.60373,-0.0508 -0.47948,0.37618 -0.91555,0.80695 -1.29424,1.27953 -0.14771,0.18371 -0.12598,0.45 0.0477,0.60806 0.55683,0.50423 0.73662,1.30637 0.44734,1.99612 -0.27618,0.65759 -0.95903,1.0814 -1.74075,1.0814 -0.25367,-0.008 -0.43435,0.1621 -0.46211,0.39273 -0.0704,0.60104 -0.0712,1.21345 -0.004,1.81937 0.0251,0.22587 0.29536,0.39339 0.52461,0.39339 0.69666,-0.0178 1.36553,0.41351 1.64611,1.09629 0.27968,0.68188 0.0999,1.47663 -0.44734,1.97825 -0.17117,0.15723 -0.19288,0.42 -0.0486,0.60283 0.37173,0.47346 0.79827,0.90429 1.26562,1.28042 0.18329,0.1477 0.45,0.12686 0.6089,-0.0482 0.47864,-0.52942 1.33515,-0.72534 1.99442,-0.44864 0.69054,0.28885 1.12489,0.98675 1.08238,1.73638 -0.0138,0.235447 0.15895,0.440417 0.39263,0.467327 0.3057,0.0357 0.61325,0.0535 0.92163,0.0535 0.29273,0 0.58551,-0.0161 0.87824,-0.0486 0.23199,-0.0256 0.40386,-0.22539 0.39607,-0.458157 -0.0268,-0.74142 0.41352,-1.42717 1.09458,-1.70602 0.65837,-0.26891 1.50536,-0.0721 1.98133,0.45078 0.15817,0.17205 0.41952,0.19282 0.60379,0.0505 0.47858,-0.37529 0.91377,-0.80571 1.29425,-1.27958 0.14763,-0.18331 0.12681,-0.45001 -0.0478,-0.60801 -0.55681,-0.50424 -0.7375,-1.30649 -0.44823,-1.99576 0.27195,-0.64884 0.92944,-1.0845 1.63663,-1.0845 l 0.0989,0.002 c 0.22938,0.0187 0.44043,-0.15806 0.46823,-0.3922 0.0705,-0.60157 0.0713,-1.21345 0.003,-1.81936 z M 444,-104.95229 c -1.47155,0 -2.66853,-1.19695 -2.66853,-2.66847 0,-1.47146 1.19698,-2.66848 2.66853,-2.66848 1.47147,0 2.66845,1.19702 2.66845,2.66848 0,1.47152 -1.19698,2.66847 -2.66845,2.66847 z"
+       inkscape:label="#path17" />
   </g>
 </svg>
diff --git a/src/gtk-3.0/assets.txt b/src/gtk-3.0/assets.txt
index 7c2fb02..a6d5fda 100644
--- a/src/gtk-3.0/assets.txt
+++ b/src/gtk-3.0/assets.txt
@@ -97,3 +97,8 @@ titlebutton-restore-alt
 titlebutton-restore-backdrop-alt
 titlebutton-restore-hover-alt
 titlebutton-restore-active-alt
+
+setting
+setting-icon
+setting-dark
+setting-icon-dark
diff --git a/src/gtk-3.0/assets/setting-dark.png b/src/gtk-3.0/assets/setting-dark.png
new file mode 100644
index 0000000..555f86e
Binary files /dev/null and b/src/gtk-3.0/assets/setting-dark.png differ
diff --git a/src/gtk-3.0/assets/setting-dark@2.png b/src/gtk-3.0/assets/setting-dark@2.png
new file mode 100644
index 0000000..c037b01
Binary files /dev/null and b/src/gtk-3.0/assets/setting-dark@2.png differ
diff --git a/src/gtk-3.0/assets/setting-icon-dark.png b/src/gtk-3.0/assets/setting-icon-dark.png
new file mode 100644
index 0000000..74eecf0
Binary files /dev/null and b/src/gtk-3.0/assets/setting-icon-dark.png differ
diff --git a/src/gtk-3.0/assets/setting-icon-dark@2.png b/src/gtk-3.0/assets/setting-icon-dark@2.png
new file mode 100644
index 0000000..c0cf299
Binary files /dev/null and b/src/gtk-3.0/assets/setting-icon-dark@2.png differ
diff --git a/src/gtk-3.0/assets/setting-icon.png b/src/gtk-3.0/assets/setting-icon.png
new file mode 100644
index 0000000..9ec1722
Binary files /dev/null and b/src/gtk-3.0/assets/setting-icon.png differ
diff --git a/src/gtk-3.0/assets/setting-icon@2.png b/src/gtk-3.0/assets/setting-icon@2.png
new file mode 100644
index 0000000..68eddf1
Binary files /dev/null and b/src/gtk-3.0/assets/setting-icon@2.png differ
diff --git a/src/gtk-3.0/assets/setting.png b/src/gtk-3.0/assets/setting.png
new file mode 100644
index 0000000..ac4ad26
Binary files /dev/null and b/src/gtk-3.0/assets/setting.png differ
diff --git a/src/gtk-3.0/assets/setting@2.png b/src/gtk-3.0/assets/setting@2.png
new file mode 100644
index 0000000..166fa15
Binary files /dev/null and b/src/gtk-3.0/assets/setting@2.png differ
diff --git a/src/gtk-3.0/gtk-compact-dark-alt.css b/src/gtk-3.0/gtk-compact-dark-alt.css
index 0882fc9..cd51ff8 100644
--- a/src/gtk-3.0/gtk-compact-dark-alt.css
+++ b/src/gtk-3.0/gtk-compact-dark-alt.css
@@ -1563,6 +1563,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4954,37 +4963,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(55, 55, 55, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting-dark.png"), url("assets/setting-dark@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  color: rgba(225, 219, 219, 0.8);
-  border: none;
-  background-color: rgba(119, 119, 119, 0.88);
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  border: none;
-  background-color: rgba(119, 119, 119, 0.98);
-  background-image: none;
-  text-shadow: none;
-  -gtk-icon-shadow: none;
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-compact-dark-solid-alt.css b/src/gtk-3.0/gtk-compact-dark-solid-alt.css
index 82b6c82..57ff808 100644
--- a/src/gtk-3.0/gtk-compact-dark-solid-alt.css
+++ b/src/gtk-3.0/gtk-compact-dark-solid-alt.css
@@ -1563,6 +1563,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4954,37 +4963,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(55, 55, 55, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting-dark.png"), url("assets/setting-dark@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  color: rgba(225, 219, 219, 0.8);
-  border: none;
-  background-color: rgba(119, 119, 119, 0.9);
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  border: none;
-  background-color: #777777;
-  background-image: none;
-  text-shadow: none;
-  -gtk-icon-shadow: none;
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-compact-dark-solid.css b/src/gtk-3.0/gtk-compact-dark-solid.css
index 8d7ffcb..5bda11d 100644
--- a/src/gtk-3.0/gtk-compact-dark-solid.css
+++ b/src/gtk-3.0/gtk-compact-dark-solid.css
@@ -1563,6 +1563,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4954,37 +4963,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(55, 55, 55, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting-dark.png"), url("assets/setting-dark@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  color: rgba(225, 219, 219, 0.8);
-  border: none;
-  background-color: rgba(119, 119, 119, 0.9);
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  border: none;
-  background-color: #777777;
-  background-image: none;
-  text-shadow: none;
-  -gtk-icon-shadow: none;
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-compact-dark.css b/src/gtk-3.0/gtk-compact-dark.css
index d3f468f..89a19cd 100644
--- a/src/gtk-3.0/gtk-compact-dark.css
+++ b/src/gtk-3.0/gtk-compact-dark.css
@@ -1563,6 +1563,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4954,37 +4963,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(55, 55, 55, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting-dark.png"), url("assets/setting-dark@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  color: rgba(225, 219, 219, 0.8);
-  border: none;
-  background-color: rgba(119, 119, 119, 0.88);
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  border: none;
-  background-color: rgba(119, 119, 119, 0.98);
-  background-image: none;
-  text-shadow: none;
-  -gtk-icon-shadow: none;
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-compact-light-alt.css b/src/gtk-3.0/gtk-compact-light-alt.css
index 4726c1c..0eeeb72 100644
--- a/src/gtk-3.0/gtk-compact-light-alt.css
+++ b/src/gtk-3.0/gtk-compact-light-alt.css
@@ -1565,6 +1565,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4964,37 +4973,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(229, 229, 229, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting.png"), url("assets/setting@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  color: rgba(40, 32, 32, 0.8);
-  border: none;
-  background-color: #fafafa;
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  border: none;
-  background-color: #afafaf;
-  background-image: none;
-  text-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  -gtk-icon-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-compact-light-solid-alt.css b/src/gtk-3.0/gtk-compact-light-solid-alt.css
index ad1d1fe..20487c1 100644
--- a/src/gtk-3.0/gtk-compact-light-solid-alt.css
+++ b/src/gtk-3.0/gtk-compact-light-solid-alt.css
@@ -1565,6 +1565,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4964,37 +4973,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(229, 229, 229, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting.png"), url("assets/setting@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  color: rgba(40, 32, 32, 0.8);
-  border: none;
-  background-color: #fafafa;
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  border: none;
-  background-color: #afafaf;
-  background-image: none;
-  text-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  -gtk-icon-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-compact-light-solid.css b/src/gtk-3.0/gtk-compact-light-solid.css
index a6c33a6..b7eea88 100644
--- a/src/gtk-3.0/gtk-compact-light-solid.css
+++ b/src/gtk-3.0/gtk-compact-light-solid.css
@@ -1565,6 +1565,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4964,37 +4973,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(229, 229, 229, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting.png"), url("assets/setting@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  color: rgba(40, 32, 32, 0.8);
-  border: none;
-  background-color: #fafafa;
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  border: none;
-  background-color: #afafaf;
-  background-image: none;
-  text-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  -gtk-icon-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-compact-light.css b/src/gtk-3.0/gtk-compact-light.css
index db33b70..ff7a141 100644
--- a/src/gtk-3.0/gtk-compact-light.css
+++ b/src/gtk-3.0/gtk-compact-light.css
@@ -1565,6 +1565,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4964,37 +4973,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(229, 229, 229, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting.png"), url("assets/setting@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  color: rgba(40, 32, 32, 0.8);
-  border: none;
-  background-color: #fafafa;
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  border: none;
-  background-color: #afafaf;
-  background-image: none;
-  text-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  -gtk-icon-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  box-shadow: 0px 1px 1px 0px rgba(16, 16, 16, 0.12), 0px 1px 2px 0px rgba(16, 16, 16, 0.06);
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-dark-alt.css b/src/gtk-3.0/gtk-dark-alt.css
index ff66b26..ab9e874 100644
--- a/src/gtk-3.0/gtk-dark-alt.css
+++ b/src/gtk-3.0/gtk-dark-alt.css
@@ -1565,6 +1565,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4952,38 +4961,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(55, 55, 55, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting-dark.png"), url("assets/setting-dark@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  border-color: rgba(255, 255, 255, 0.12);
-  color: rgba(221, 213, 213, 0.8);
-  background-color: rgba(119, 119, 119, 0.88);
-  background-image: none;
-  box-shadow: none;
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  background-color: rgba(119, 119, 119, 0.98);
-  background-image: none;
-  border-color: rgba(255, 255, 255, 0.12);
-  text-shadow: none;
-  -gtk-icon-shadow: none;
-  box-shadow: none;
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-dark-solid-alt.css b/src/gtk-3.0/gtk-dark-solid-alt.css
index 0a047ce..2a3545b 100644
--- a/src/gtk-3.0/gtk-dark-solid-alt.css
+++ b/src/gtk-3.0/gtk-dark-solid-alt.css
@@ -1565,6 +1565,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4940,38 +4949,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(55, 55, 55, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting-dark.png"), url("assets/setting-dark@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  border-color: rgba(255, 255, 255, 0.12);
-  color: rgba(221, 213, 213, 0.8);
-  background-color: rgba(119, 119, 119, 0.9);
-  background-image: none;
-  box-shadow: none;
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  background-color: #777777;
-  background-image: none;
-  border-color: rgba(255, 255, 255, 0.12);
-  text-shadow: none;
-  -gtk-icon-shadow: none;
-  box-shadow: none;
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-dark-solid.css b/src/gtk-3.0/gtk-dark-solid.css
index 7dbbb33..ee56809 100644
--- a/src/gtk-3.0/gtk-dark-solid.css
+++ b/src/gtk-3.0/gtk-dark-solid.css
@@ -1565,6 +1565,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4952,38 +4961,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(55, 55, 55, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting-dark.png"), url("assets/setting-dark@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  border-color: rgba(255, 255, 255, 0.12);
-  color: rgba(221, 213, 213, 0.8);
-  background-color: rgba(119, 119, 119, 0.9);
-  background-image: none;
-  box-shadow: none;
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  background-color: #777777;
-  background-image: none;
-  border-color: rgba(255, 255, 255, 0.12);
-  text-shadow: none;
-  -gtk-icon-shadow: none;
-  box-shadow: none;
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-dark.css b/src/gtk-3.0/gtk-dark.css
index 4e151f6..0a9569d 100644
--- a/src/gtk-3.0/gtk-dark.css
+++ b/src/gtk-3.0/gtk-dark.css
@@ -1565,6 +1565,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4952,38 +4961,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(55, 55, 55, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting-dark.png"), url("assets/setting-dark@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  border-color: rgba(255, 255, 255, 0.12);
-  color: rgba(221, 213, 213, 0.8);
-  background-color: rgba(119, 119, 119, 0.88);
-  background-image: none;
-  box-shadow: none;
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  background-color: rgba(119, 119, 119, 0.98);
-  background-image: none;
-  border-color: rgba(255, 255, 255, 0.12);
-  text-shadow: none;
-  -gtk-icon-shadow: none;
-  box-shadow: none;
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-light-alt.css b/src/gtk-3.0/gtk-light-alt.css
index 0b40e06..a5e1144 100644
--- a/src/gtk-3.0/gtk-light-alt.css
+++ b/src/gtk-3.0/gtk-light-alt.css
@@ -1567,6 +1567,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4980,38 +4989,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(229, 229, 229, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting.png"), url("assets/setting@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  border-color: rgba(0, 0, 0, 0.12);
-  color: rgba(34, 28, 28, 0.8);
-  background-color: #fafafa;
-  background-image: linear-gradient(0deg, #f8f8f8 0%, #ffffff 100%);
-  box-shadow: none;
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  background-color: #afafaf;
-  background-image: none;
-  border-color: rgba(0, 0, 0, 0.12);
-  text-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  -gtk-icon-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  box-shadow: none;
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-light-solid-alt.css b/src/gtk-3.0/gtk-light-solid-alt.css
index 6b4d2fb..cacf7fc 100644
--- a/src/gtk-3.0/gtk-light-solid-alt.css
+++ b/src/gtk-3.0/gtk-light-solid-alt.css
@@ -1567,6 +1567,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4980,38 +4989,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(229, 229, 229, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting.png"), url("assets/setting@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  border-color: rgba(0, 0, 0, 0.12);
-  color: rgba(34, 28, 28, 0.8);
-  background-color: #fafafa;
-  background-image: linear-gradient(0deg, #f8f8f8 0%, #ffffff 100%);
-  box-shadow: none;
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  background-color: #afafaf;
-  background-image: none;
-  border-color: rgba(0, 0, 0, 0.12);
-  text-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  -gtk-icon-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  box-shadow: none;
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-light-solid.css b/src/gtk-3.0/gtk-light-solid.css
index ab85c2f..07b2269 100644
--- a/src/gtk-3.0/gtk-light-solid.css
+++ b/src/gtk-3.0/gtk-light-solid.css
@@ -1567,6 +1567,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4980,38 +4989,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(229, 229, 229, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting.png"), url("assets/setting@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  border-color: rgba(0, 0, 0, 0.12);
-  color: rgba(34, 28, 28, 0.8);
-  background-color: #fafafa;
-  background-image: linear-gradient(0deg, #f8f8f8 0%, #ffffff 100%);
-  box-shadow: none;
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  background-color: #afafaf;
-  background-image: none;
-  border-color: rgba(0, 0, 0, 0.12);
-  text-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  -gtk-icon-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  box-shadow: none;
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/gtk-light.css b/src/gtk-3.0/gtk-light.css
index e3618d1..ef672cf 100644
--- a/src/gtk-3.0/gtk-light.css
+++ b/src/gtk-3.0/gtk-light.css
@@ -1567,6 +1567,15 @@ headerbar.default-decoration button.titlebutton,
   padding: 0;
 }
 
+headerbar.default-decoration button.titlebutton.appmenu, headerbar.default-decoration button.titlebutton.appmenu:active, headerbar.default-decoration button.titlebutton.appmenu:checked,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:active,
+.default-decoration.titlebar:not(headerbar) button.titlebutton.appmenu:checked {
+  background-color: transparent;
+  box-shadow: none;
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
+}
+
 headerbar.default-decoration,
 .csd headerbar.default-decoration, headerbar.default-decoration:backdrop,
 .csd headerbar.default-decoration:backdrop,
@@ -4980,38 +4989,30 @@ messagedialog.csd decoration {
   box-shadow: none;
 }
 
-headerbar button.titlebutton,
-.titlebar button.titlebutton {
-  min-width: 24px;
-  min-height: 24px;
-  margin: 0;
-  padding: 0;
-  border-color: transparent;
-  background-color: transparent;
-  background-image: none;
-  box-shadow: none;
-  background-color: rgba(229, 229, 229, 0);
+headerbar button.titlebutton.appmenu,
+.titlebar button.titlebutton.appmenu {
+  transition: background-color 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.1s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  color: transparent;
+  background-image: -gtk-scaled(url("assets/setting.png"), url("assets/setting@2.png"));
+  background-repeat: no-repeat;
+  background-position: center;
 }
 
-headerbar button.titlebutton:hover,
-.titlebar button.titlebutton:hover {
-  border-color: rgba(0, 0, 0, 0.12);
-  color: rgba(34, 28, 28, 0.8);
-  background-color: #fafafa;
-  background-image: linear-gradient(0deg, #f8f8f8 0%, #ffffff 100%);
-  box-shadow: none;
+headerbar button.titlebutton.appmenu image,
+.titlebar button.titlebutton.appmenu image {
+  opacity: 0;
 }
 
-headerbar button.titlebutton:active, headerbar button.titlebutton:checked,
-.titlebar button.titlebutton:active,
-.titlebar button.titlebutton:checked {
-  color: #ffffff;
-  background-color: #afafaf;
-  background-image: none;
-  border-color: rgba(0, 0, 0, 0.12);
-  text-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  -gtk-icon-shadow: 0 -1px rgba(255, 255, 255, 0.04), -1px 0px rgba(32, 32, 32, 0.05), 1px 0px rgba(32, 32, 32, 0.05), 0px 1px rgba(32, 32, 32, 0.3), 0px 2px rgba(32, 32, 32, 0.05);
-  box-shadow: none;
+headerbar button.titlebutton.appmenu:active, headerbar button.titlebutton.appmenu:checked,
+.titlebar button.titlebutton.appmenu:active,
+.titlebar button.titlebutton.appmenu:checked {
+  transition: background-color 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94), background-image 0, background-size 0;
+  background-image: -gtk-scaled(url("assets/setting-icon.png"), url("assets/setting-icon@2.png"));
+}
+
+headerbar button.titlebutton.appmenu:backdrop,
+.titlebar button.titlebutton.appmenu:backdrop {
+  background-image: -gtk-scaled(url("assets/setting-icon-dark.png"), url("assets/setting-icon-dark@2.png"));
 }
 
 headerbar button.titlebutton.close, headerbar button.titlebutton.maximize, headerbar button.titlebutton.minimize, headerbar button.titlebutton.restore,
diff --git a/src/gtk-3.0/sass/_common.scss b/src/gtk-3.0/sass/_common.scss
index 3b3825a..f2972ef 100644
--- a/src/gtk-3.0/sass/_common.scss
+++ b/src/gtk-3.0/sass/_common.scss
@@ -3,6 +3,7 @@
 }
 
 $asset_suffix: if($variant=='dark', '-dark', ''); // use dark assets in dark variant
+$con_asset_suffix: if($variant=='dark', '', '-dark');
 $darker_asset_suffix: if($darker=='true', '-dark', $asset_suffix);
 $alt_suffix: if($titlebutton=='alt', '-alt', '');
 $bt_radius: 5px;
@@ -1226,6 +1227,15 @@ headerbar,
       min-height: 16px;
       margin: 0;
       padding: 0;
+
+      &.appmenu {
+        &, &:active, &:checked {
+          background-color: transparent;
+          box-shadow: none;
+          background-image: -gtk-scaled(url("assets/setting-icon#{$con_asset_suffix}.png"),
+                                        url("assets/setting-icon#{$con_asset_suffix}@2.png"));
+        }
+      }
     }
   }
 
@@ -3856,20 +3866,35 @@ headerbar,
 .titlebar {
 
   button.titlebutton {
-    min-width: 24px;
-    min-height: 24px;
-    margin: 0;
-    padding: 0;
+    &.appmenu {
+      transition: background-color 0.1s $ease-out-quad,
+                  box-shadow 0.1s $ease-out-quad,
+                  background-image 0,
+                  background-size 0;
 
-    @include button(undecorated);
-    background-color: transparentize($header_bg, 1);
+      color: transparent;
+      background-image: -gtk-scaled(url("assets/setting#{$asset_suffix}.png"),
+                                    url("assets/setting#{$asset_suffix}@2.png"));
+      background-repeat: no-repeat;
+      background-position: center;
 
-    &:hover {
-      @include button(header-hover);
-    }
-    &:active, &:checked {
-      @include button(header-active);
+      image { opacity: 0; } // Make menu button default icon invisible
+
+      &:active, &:checked {
+        transition: background-color 0.3s $ease-out-quad,
+                    box-shadow 0.3s $ease-out-quad,
+                    background-image 0,
+                    background-size 0;
+        background-image: -gtk-scaled(url("assets/setting-icon#{$asset_suffix}.png"),
+                                      url("assets/setting-icon#{$asset_suffix}@2.png"));
+      }
+
+      &:backdrop {
+        background-image: -gtk-scaled(url("assets/setting-icon#{$con_asset_suffix}.png"),
+                                      url("assets/setting-icon#{$con_asset_suffix}@2.png"));
+      }
     }
+
     &.close, &.maximize, &.minimize, &.restore {
       min-width: 16px;
       min-height: 16px;