Button: hover_color, hover_border_color

dash-frontend/assets/gui/templates.xml

@@ -5,6 +5,8 @@
       height="82"
       color="#00000033"
       border_color="#FFFFFF77"
+      hover_color="~accent"
+      hover_border_color="#FFFFFF"
       round="8">
       <div gap="8"
         align_items="center"

dash-frontend/assets/gui/theme.xml

@@ -1,6 +1,7 @@
 <layout>
   <theme>
     <var key="menu_dark" value="#0A0A0ACC" />
+    <var key="accent" value="#008cff" />
     <var key="background_dark" value="#0d131acc" />
     <var key="background_light" value="#244179aa" />
     <var key="bottom_panel" value="#141e28" />