update container class to avoid confusion

margin-and-padding/margin-and-padding-2/index.html

@@ -11,7 +11,7 @@
   <div class="card">
     <h1 class="title">I'm a card</h1>
     <div class="content">I have content inside me..lorem ipsum blah blah blah. Here's some stuff you need to read.</div>
-    <div class="button">and a <button>BIG BUTTON</button></div>
+    <div class="button-container">and a <button>BIG BUTTON</button></div>
   </div>
 </body>
 </html>

margin-and-padding/margin-and-padding-2/solution/solution.css

@@ -17,7 +17,7 @@ body {
   background: #e3f4ff;
 }
 
-.button {
+.button-container {
   background: #e3f4ff;
 }
 
@@ -50,7 +50,7 @@ We separated it out here to make it extra clear what has changed. */
   padding: 16px 8px;
 }
 
-.button {
+.button-container {
   text-align: center;
   padding: 8px;
 }

margin-and-padding/margin-and-padding-2/solution/solution.html

@@ -11,7 +11,7 @@
   <div class="card">
     <h1 class="title">I'm a card</h1>
     <div class="content">I have content inside me..lorem ipsum blah blah blah. Here's some stuff you need to read.</div>
-    <div class="button">and a <button>BIG BUTTON</button></div>
+    <div class="button-container">and a <button>BIG BUTTON</button></div>
   </div>
 </body>
 </html>

margin-and-padding/margin-and-padding-2/style.css

@@ -17,7 +17,7 @@ body {
   background: #e3f4ff;
 }
 
-.button {
+.button-container {
   background: #e3f4ff;
 }