Added basic breeze-gtk theme compat

src/style.css

@@ -11,7 +11,8 @@
 .notification-row {
   outline: none;
 }
-.notification-row:focus {
+.notification-row:focus,
+.notification-row:hover {
   background: @bg-focus;
 }
 
@@ -32,8 +33,9 @@
   background: black;
   color: white;
   text-shadow: none;
-  padding: 0;
+  padding: 0 2px;
   box-shadow: 0px 2px 4px 2px rgba(0, 0, 0, 0.3);
+  border-radius: 100%;
 }
 .close-button:hover {
   background: rgb(30, 30, 30);
@@ -43,6 +45,7 @@
 .notification-default-action,
 .notification-action {
   padding: 4px;
+  margin: 0;
   box-shadow: none;
   background: @bg;
   border: 1px solid @border-color;