Added some elevation affects to the side nav campaigns and campaign details page, is this something that we want across the app?

campaign.php

@@ -29,14 +29,14 @@ if(isset($_GET['campaign_id'])){
 
   ?>
 
-  <ol class="breadcrumb">
+  <ol class="breadcrumb elevation-2">
     <li class="breadcrumb-item">
       <a href="campaigns.php">Campaigns</a>
     </li>
     <li class="breadcrumb-item active"><?php echo $campaign_name; ?></li>
   </ol>
 
-  <div class="card card-body">
+  <div class="card card-body elevation-3">
     <h6 class="text-secondary">CAMPAIGN</h6>
     <h1><?php echo $campaign_name; ?></h1>
   </div>
@@ -96,7 +96,7 @@ if(isset($_GET['campaign_id'])){
 
 ?>
 
-<div class="card card-dark">
+<div class="card card-dark elevation-3">
   <div class="card-header py-3">
     <h3 class="card-title"><i class="fa fa-fw fa-envelope"></i> Messages</h3>
   </div>

campaigns.php

@@ -91,7 +91,7 @@
 
 ?>
 
-<div class="card card-dark">
+<div class="card card-dark elevation-3">
   <div class="card-header py-2">
     <h3 class="card-title mt-2"><i class="fa fa-fw fa-envelope"></i> Mailing Campaigns</h3>
     <div class="card-tools">

side_nav.php

@@ -1,5 +1,5 @@
 <!-- Main Sidebar Container -->
-<aside class="main-sidebar sidebar-dark-primary d-print-none">
+<aside class="main-sidebar sidebar-dark-primary elevation-3 d-print-none">
 
   <!-- Sidebar -->
   <div class="sidebar">