adicionando banner desktop e mobile

css/base/reset.css

@@ -1,4 +1,9 @@
 /*! normalize.css v8.0.1 | MIT License | github.com/necolas/normalize.css */
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
 
  html {
     line-height: 1.15; 

css/layout/header.css

@@ -2,10 +2,8 @@ header {
     position: absolute;
     width: 100%;
     height: 100px;
-    left: 0px;
     top: 0px;
     background: #000000;
-    margin: auto;
     display: flex;
     align-items: center;
     justify-content: center;
@@ -14,4 +12,6 @@ header {
 header img {
     width: 83px;
     height: 43px;
-}
+  
+}
+

css/layout/main.css

@@ -0,0 +1,18 @@
+.main_banner_desktop,.main_banner_mobile {
+    width: 100%;
+    height: auto;
+    position: absolute;
+    top: 100px;
+}
+
+@media screen and (max-width: 415px) {
+    .main_banner_desktop {
+        display: none;
+    }
+}
+
+@media screen and (min-width: 415px) {
+    .main_banner_mobile {
+        display: none;
+    }
+}

index.html

@@ -21,5 +21,12 @@
            <img src="./assets/img/Logo M3 [branco] (4) 1.svg" alt="Logo M3 Academy"> 
         </a> 
     </header>
+    <main>
+        <section>
+            <img src="./assets/img/Rectangle-9-desktop.webp" alt="Imagem Notebook Desktop" class="main_banner_desktop">
+            <img src="./assets/img/Rectangle-9-mobile.webp" alt="Imagem Notebook Mobile" class="main_banner_mobile">
+        </section>
+    </main>
+    
 </body>
 </html>