adicionando os banners principais, desktop e mobile

assets/style/main.css

@@ -10,5 +10,20 @@
     padding: 29px 0;
 }
 .header-logo{
-    display: block
+    display: block;
 }
+.main-banner{
+    width: 100%;
+}
+@media screen and (max-width: 414px) {
+    .main-banner-desktop {
+        display: none;
+    }
+}
+
+@media screen and (min-width: 415px) {
+    .main-banner-mobile {
+        display: none;
+    }
+}
+ 

index.html

@@ -13,6 +13,12 @@
                 <img class="header-logo" src="assets/image/Logo-M3Academy 1.svg" alt="Logo M3 Academy">
             </a>
         </header>
+        <main>
+            <section>
+                <img class="main banner main-banner-desktop" src="assets/image/main-banner-desktop.png" alt="banner principal desktop"/>
+                <img class="main banner main-banner-mobile" src="assets/image/main-banner-mobile.png" alt="banner principal mobile"/>
+            </section>
+        </main>
     
 </body>
 </html>