Adiciona os banners principais desktop e mobile

assets/styles/main.css

@@ -13,4 +13,20 @@
 
 .header-logo {
     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;
+    }
+}

inde.html

@@ -17,5 +17,12 @@
                 <img class="header-logo" src="./assets/images/m3-logo.png" alt="Logo M3" /> 
             </a>
         </header>
+
+        <main>
+           <section>
+              <img class="main-banner main-banner-desktop" src="./assets/images/main-banner-desktop.png" alt="Banner Principal Desktop" />
+              <img class="main-banner main-banner-mobile" src="./assets/images/main-banner-mobile.png" alt="Banner Principal Mobile" />
+           </section>
+        </main>
     </body>
 </html>