--- a/devtools/client/responsive.html/index.css
+++ b/devtools/client/responsive.html/index.css
@@ -27,31 +27,24 @@
 
 * {
   box-sizing: border-box;
 }
 
 #root,
 html, body {
   margin: 0;
-  height: 100%;
-}
-
-#root {
-  display: flex;
-  flex-direction: column;
-  justify-content: center;
 }
 
 #app {
   /* Center the viewports container */
   display: flex;
-  justify-content: center;
   align-items: center;
   flex-direction: column;
+  height: 100vh;
 
   /* Snap to the top of the app when there isn't enough vertical space anymore
      to center the viewports (so we don't lose the global toolbar) */
   position: sticky;
   top: 0;
 }
 
 /**
@@ -80,17 +73,17 @@ html, body {
 /**
  * Global Toolbar
  */
 
 #global-toolbar {
   color: var(--theme-body-color-alt);
   border-radius: 2px;
   box-shadow: var(--rdm-box-shadow);
-  margin: 30px 0;
+  margin: 10% 0 30px 0;
   padding: 4px 5px;
   display: inline-flex;
   -moz-user-select: none;
 }
 
 #global-toolbar > .title {
   border-right: 1px solid var(--theme-splitter-color);
   padding: 1px 6px 0 2px;