Update index.html

index.html

@@ -173,7 +173,7 @@
       .slide3{
     background-image: url('https://png.pngtree.com/thumb_back/fh260/back_our/20190620/ourmid/pngtree-guitar-interest-class-enrollment-cartoon-geometric-blue-banner-image_171320.jpg');
     height: 555px;
-        width: 1200px;
+        width: 100%;
     font-size: 28px;
     font-family: 'Pacifico', cursive;
     background-size: cover;