Added the solution while using all of the code. (#25675)

curriculum/challenges/english/01-responsive-web-design/basic-css/adjust-the-margin-of-an-element.english.md

@@ -86,6 +86,43 @@ tests:
 <section id='solution'>
 
 ```js
-// solution required
+<style>
+  .injected-text {
+    margin-bottom: -25px;
+    text-align: center;
+  }
+
+  .box {
+    border-style: solid;
+    border-color: black;
+    border-width: 5px;
+    text-align: center;
+  }
+
+  .yellow-box {
+    background-color: yellow;
+    padding: 10px;
+  }
+
+  .red-box {
+    background-color: crimson;
+    color: #fff;
+    padding: 20px;
+    margin: 20px;
+  }
+
+  .blue-box {
+    background-color: blue;
+    color: #fff;
+    padding: 20px;
+    margin: 20px;
+  }
+</style>
+<h5 class="injected-text">margin</h5>
+
+<div class="box yellow-box">
+  <h5 class="box red-box">padding</h5>
+  <h5 class="box blue-box">padding</h5>
+</div>
 ```
 </section>