Add sticky footer layout

client/layouts/StickyFooter.jsx

@@ -0,0 +1,57 @@
+import React from 'react';
+
+import DetailsLayout from '../DetailsLayout';
+import BrowserFrame from '../placeholders/BrowserFrame';
+import SampleCode from '../SampleCode';
+import useDocumentTitle from '../useDocumentTitle';
+
+const StickyFooter = () => {
+    useDocumentTitle('CSS Layout ∙ Sticky footer');
+
+    return (
+        <DetailsLayout name="Sticky footer">
+            <div className="lh-copy mb3">
+                The footer is always sticky at the bottom if the main content is short.
+            </div>
+            <BrowserFrame
+                content={
+                    <div className="h-100 flex flex-column ba b--black-30 bw1">
+                        <div className="flex-shrink-0 bb b--black-30 bw1 pa3">
+                            Header
+                        </div>
+                        <div className="flex-grow-1 pa3">
+                            Content
+                        </div>
+                        <div className="flex-shrink-0 bt b--black-30 bw1 pa3">
+                            Footer
+                        </div>
+                    </div>
+                }
+                source={
+<SampleCode
+lang="html"
+code={`
+<div style="
+    display: flex;
+    flex-direction: column;
+    height: '100%';
+">
+    <header style="flex-shrink: 0;">
+        ...
+    </header>
+    <main style="flex-grow: 1;">
+        ...
+    </main>
+    <footer style="flex-shrink: 0;">
+        ...
+    </footer>
+</div>
+`}
+/>
+                }
+            />
+        </DetailsLayout>
+    );
+};
+
+export default StickyFooter;