user-friendly wallpaper; some fixes

.config/ags/scss/_lib_classes.scss

@@ -139,6 +139,13 @@
     font-style: italic;
 }
 
+.btn-primary {
+    @include full-rounding;
+    background-color: $primary;
+    color: $onPrimary;
+    padding: 0.682rem 1.023rem;
+}
+
 .titlefont {
     @include titlefont;
 }

.config/ags/scss/_overview.scss

@@ -116,7 +116,7 @@
 .overview-tasks-window {
     @include normal-rounding;
     @include menu_decel;
-    background-color: $l_t_secondaryContainer;
+    background-color: $t_surfaceVariant;
     color: $onSecondaryContainer;
     border: 0.068rem solid $t_t_t_onSecondaryContainer;
 }