fix: Change close button hover color to something more neutral

No longer shows HelloSign Blue (cerulean). This is especially important for users with white labeling enabled

Author: nathanbuchar

src/sass/embedded.scss

@@ -68,14 +68,14 @@
   height: 100%;
   width: 100%;
   border: none;
-  background-color: #1a1a1a;
+  background-color: $hellosign-castle-rock;
   transition: background-color 0.35s ease;
   will-change: background-color;
   box-shadow: 0px 3px 9px 0px rgba(0, 0, 0, 0.25);
   cursor: pointer;
 
   &:hover {
-    background-color: $hellosign-cerulean;
+    background-color: $hellosign-ashen;
   }
 
   &::before,

src/sass/variables.scss

@@ -1,2 +1,4 @@
+$hellosign-castle-rock: #1A1A1A;
+$hellosign-ashen: #4E4E4E;
 $hellosign-cerulean: #00B3E6;
 $hellosign-plume: #F7F8F9;