--- a/devtools/shim/aboutdevtools/aboutdevtools.css
+++ b/devtools/shim/aboutdevtools/aboutdevtools.css
@@ -20,41 +20,36 @@
   --white: #ffffff;
 
   /* Shared variables */
   --line-height: 1.5em;
 }
 
 html, body {
   min-width: 600px;
-  height: 100%;
+}
+
+body {
+  margin-top: 17vh;
 }
 
 p {
   line-height: var(--line-height);
 }
 
 .box {
-  width: 100%;
   max-width: 850px;
   display: flex;
   flex-shrink: 0;
-}
-
-#install-page .box {
-  padding: 17% 0 50px 0;
-}
-
-#welcome-page .box {
-  padding: 50px 0;
+  padding: 0 0 50px 0;
+  /* Compensate for the optional scrollbar. */
+  margin-right: calc(100% - 100vw);
 }
 
 .wrapper {
-  width: 100%;
-  height: 100%;
   display: flex;
   flex-direction: column;
   align-items: center;
 }
 
 .left-pane {
   width: 300px;
   height: 300px;