[MD settings] refine routing function

chrome/browser/resources/settings/settings_page_css.html

Index: chrome/browser/resources/settings/settings_page_css.html
diff --git a/chrome/browser/resources/settings/settings_page_css.html b/chrome/browser/resources/settings/settings_page_css.html
index d888b44147e284753760bb725eaace1dd8092713..1b6d6b73d0f2c413b0a7e91d3d058dc0e98fbb87 100644
--- a/chrome/browser/resources/settings/settings_page_css.html
+++ b/chrome/browser/resources/settings/settings_page_css.html
@@ -7,7 +7,7 @@
         --settings-page-padding-top: 21px;
         box-sizing: border-box;
         display: block;
-        height: 100%;
+        height: inherit;
         margin: 0 auto;
         max-width: 960px;
         min-width: 622px;
@@ -15,7 +15,11 @@
         width: 96%;
       }
 
-      :host > * {
+      :host > div {
+        height: inherit;
+      }
+
+      :host > div > * {
         /* The margin and padding here are doing two things: make the total
          * separation 24px; and make scrollIntoView align the section header
          * with the top item in the side nav menu. Both things are desired