show focus on sprite visibility buttons

src/components/sprite-info/sprite-info.css

@@ -62,6 +62,11 @@
     border-bottom-left-radius: $form-radius;
 }
 
+.radio-left:focus {
+    border-color: #4c97ff;
+    box-shadow: inset 0 0 0 -2px rgba(0, 0, 0, 0.1);
+}
+
 .radio-right {
     border-bottom: 1px solid $form-border;
     border-top: 1px solid $form-border;
@@ -70,6 +75,11 @@
     border-bottom-right-radius: $form-radius;
 }
 
+.radio-right:focus {
+    border-color: #4c97ff;
+    box-shadow: inset 0 0 0 -2px rgba(0, 0, 0, 0.1);
+}
+
 .icon {
     width: 100%;
     height: 100%;