Live code fixing

Author: aaccurso

css3/basic-css-selectors/index.html

@@ -246,7 +246,7 @@ <h3>Pseudo-class</h3>
 }</code></pre>
         </article>
         <article>
-            <header class="css-property title">:first y :last</header>
+            <header class="css-property title">:first-child y :last-child</header>
             <p>Selecciona el primer o último hijo.</p>
             <div class="css-element">
                 <div class="button-group">
@@ -258,11 +258,11 @@ <h3>Pseudo-class</h3>
                 </div>
             </div>
             <pre><code class="html">&lt;div class=&quot;button-group&quot;&gt;
-&lt;div class=&quot;button&quot;&gt;Primero&lt;/div&gt;
-&lt;div class=&quot;button&quot;&gt;Otro&lt;/div&gt;
-&lt;div class=&quot;button&quot;&gt;Otro&lt;/div&gt;
-&lt;div class=&quot;button&quot;&gt;Otro&lt;/div&gt;
-&lt;div class=&quot;button&quot;&gt;&Uacute;ltimo&lt;/div&gt;
+    &lt;div class=&quot;button&quot;&gt;Primero&lt;/div&gt;
+    &lt;div class=&quot;button&quot;&gt;Otro&lt;/div&gt;
+    &lt;div class=&quot;button&quot;&gt;Otro&lt;/div&gt;
+    &lt;div class=&quot;button&quot;&gt;Otro&lt;/div&gt;
+    &lt;div class=&quot;button&quot;&gt;&Uacute;ltimo&lt;/div&gt;
 &lt;/div&gt;</code><code class="css">.button-group .button {
     display: inline;
     background-color: #007bff;

css3/box-model/index.html

@@ -56,7 +56,7 @@ <h3 class="css-property">Box Size</h3>
         </div>
         <p>
             Calcular el área total del elemento anterior. <span class="hover-to-show">Hover para ver la solución!</span>
-            <span class="css-property">width: 360px; height: 160px;</span>
+            <span class="css-property">width: 420px; height: 220px;</span>
         </p>
     </section>
 </body>

css3/z-index/index.html

@@ -61,13 +61,13 @@ <h3 class="css-property">z-index: &lt;entero&gt;;</h3>
                 Este elemento tiene <span class="css-property">position: relative;</span>
             </p>
             <div class="css-element absolute-1">
-                1) Primer elemento con <div class="css-property">postition: absolute; z-index: 1;</div>
+                1) Primer elemento con <div class="css-property">postition: absolute; z-index: 3;</div>
             </div>
             <div class="css-element absolute-2">
                 2) Segundo elemento con <div class="css-property">postition: absolute; z-index: 2;</div>
             </div>
             <div class="css-element absolute-3">
-                3) Tercer elemento con <div class="css-property">postition: absolute; z-index: 3;</div>
+                3) Tercer elemento con <div class="css-property">postition: absolute; z-index: 1;</div>
             </div>
         </div>
         <p>
@@ -79,13 +79,13 @@ <h3 class="css-property">z-index: &lt;entero&gt;;</h3>
                     Este elemento tiene <span class="css-property">position: relative;</span> y establece un nuevo contexto de apilamiento con <span class="css-property">z-index: 0;</span>
                 </p>
                 <div class="css-element absolute-1">
-                    1) Primer elemento con <div class="css-property">postition: absolute; z-index: 1;</div>
+                    1) Primer elemento con <div class="css-property">postition: absolute; z-index: 3;</div>
                 </div>
                 <div class="css-element absolute-2">
                     2) Segundo elemento con <div class="css-property">postition: absolute; z-index: 2;</div>
                 </div>
                 <div class="css-element absolute-3">
-                    3) Tercer elemento con <div class="css-property">postition: absolute; z-index: 3;</div>
+                    3) Tercer elemento con <div class="css-property">postition: absolute; z-index: 1;</div>
                 </div>
             </div>
             <div class="css-element outer">