adapt header image to window size changes

Author: sawhney-medha

_layouts/default_about.liquid

@@ -19,9 +19,10 @@
       background-image: url('/assets/img/lab_header.jpeg');
       background-repeat: no-repeat;
       background-size: contain;
-      background-position: center center;
-      height: 100vh; /* Adjust this if there is white space before the image or if image gets cuts off */
-      margin-bottom: 2em;
+      background-position: top center;
+      padding-bottom: 56.25%; /* 16:9 aspect ratio */
+      height: 0
+      margin-bottom: 0;
       margin-top: -0.0em;
       width: 100%;
     "></div>