Added color Schemes support. Added settings GUI in colorscheme-osd

.config/ags/scss/_common.scss

@@ -209,6 +209,31 @@ popover {
     color: $onSecondaryContainer;
 }
 
+.multipleselection-container {
+}
+
+.multipleselection-btn {
+    @include small-rounding;
+    padding: 0rem 0.341rem;
+    border: 0.034rem solid $outlineVariant;
+}
+
+.multipleselection-btn:focus,
+.multipleselection-btn:hover {
+    background-color: $hovercolor;
+}
+
+.multipleselection-btn-enabled {
+    background-color: $secondaryContainer;
+    color: $onSecondaryContainer;
+}
+
+.multipleselection-btn-enabled:hover,
+.multipleselection-btn-enabled:focus {
+    background-color: $secondaryContainer;
+    color: $onSecondaryContainer;
+}
+
 .gap-v-5 {
     min-height: 0.341rem;
 }
@@ -231,4 +256,4 @@ popover {
 
 .gap-h-15 {
     min-width: 1.023rem;
-}
+}