Update

Test/Teacher/teacher/includes/sidebar.php

-   <div class="app-sidebar sidebar-shadow" style="background-color:#A9CCE3 ;">
+<div class="app-sidebar sidebar-shadow" style="background-color:#A9CCE3;">
                     <div class="app-header__logo">
                         <div class="logo-src"></div>
                         <div class="header__pane ml-auto">

Test/conn.php

@@ -3,13 +3,12 @@
 $host = "localhost";
 $user = "root";
 $pass = "";
-$db   = "cee_db";
-$conn = null;
+$db   = "id17041785_cee_db";
 
 try {
   $conn = new PDO("mysql:host={$host};dbname={$db};",$user,$pass);
 } catch (Exception $e) {
-  
+  exit("Error: ". $e->getMessage());
 }