diff --git a/docs/_brand/apple-touch-icon.png b/docs/_brand/apple-touch-icon.png
new file mode 100644
index 0000000..b360cfb
Binary files /dev/null and b/docs/_brand/apple-touch-icon.png differ
diff --git a/docs/_brand/favicon.ico b/docs/_brand/favicon.ico
new file mode 100644
index 0000000..49c6357
Binary files /dev/null and b/docs/_brand/favicon.ico differ
diff --git a/docs/_brand/favicon.svg b/docs/_brand/favicon.svg
new file mode 100644
index 0000000..f0f06b0
--- /dev/null
+++ b/docs/_brand/favicon.svg
@@ -0,0 +1,20 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32">
+  <!-- Impulso mark: an impulse response with its 68% and 90% credible bands,
+       paper on a brand-oxblood tile, after the Impulso figure on the
+       quantclimate.com landing page. The response rises off the zero line
+       and decays out past the tile's right edge. The zero line sits on whole
+       pixels at 16px and 32px. favicon.ico and apple-touch-icon.png are
+       rasterised from this file; see html_favicon in docs/conf.py. -->
+  <clipPath id="tile"><rect width="32" height="32" rx="7"/></clipPath>
+  <rect width="32" height="32" rx="7" fill="#7a2e2a"/>
+  <g clip-path="url(#tile)">
+    <g fill="#faf9f7">
+      <path fill-opacity=".18" d="M5 25C6.5 24.6 8.1 4 13 3.9C15.2 3.9 18.7 10.8 20 12.8C23.4 18.1 26.7 21.5 33 22.8L33 25.8C27.9 25.4 24.3 24.4 20 21.7C18.2 20.5 15.1 18.1 13 18.1C8.9 18.1 6.4 24.9 5 25Z"/>
+      <path fill-opacity=".28" d="M5 25C6.5 24.7 8.1 7.6 13 7.6C15.1 7.6 18.6 13.3 20 15.1C23.7 19.9 27 22.5 33 23.6L33 25C27.6 24.4 24.1 23 20 19.4C18.3 17.9 15.1 14.4 13 14.4C8.5 14.4 6.4 24.8 5 25Z"/>
+    </g>
+    <g fill="none" stroke="#faf9f7" stroke-linecap="round">
+      <path stroke-opacity=".5" stroke-width="2" d="M5 25H33"/>
+      <path stroke-width="2.6" d="M5 25C6.4 24.7 8.3 11 13 11C15.1 11 18.5 15.6 20 17.2C23.9 21.5 27.3 23.4 33 24.3"/>
+    </g>
+  </g>
+</svg>
diff --git a/docs/conf.py b/docs/conf.py
index adb43f0..e1b37bf 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -168,9 +168,18 @@
 ogp_social_cards = {"enable": False}
 html_static_path = ["stylesheets"]
 html_css_files = ["extra.css"]
+# The theme links the SVG favicon from every page. The ICO and the iOS
+# home-screen icon go to the site root, where browsers look for them by
+# default. Both are rendered from the SVG; after editing it, regenerate them:
+#     cd docs/_brand
+#     for s in 16 32 48; do rsvg-convert -w $s -h $s favicon.svg -o /tmp/f$s.png; done
+#     magick /tmp/f16.png /tmp/f32.png /tmp/f48.png favicon.ico
+#     sed 's/ rx="7"//g' favicon.svg | rsvg-convert -w 180 -h 180 -o apple-touch-icon.png
+# (The apple-touch-icon is square-cornered because iOS applies its own mask.)
+html_favicon = "_brand/favicon.svg"
 # Cloudflare serves the site; _redirects maps directory URLs to index.html and
 # _headers adds the CORS header that GitHub Pages used to send.
-html_extra_path = ["_redirects", "_headers"]
+html_extra_path = ["_redirects", "_headers", "_brand/favicon.ico", "_brand/apple-touch-icon.png"]
 html_theme_options = {
     "accent_color": "crimson",  # names the token family; stylesheets/extra.css re-tones the crimson scale to ledger oxblood
     "color_mode": "auto",  # follow the reader's light/dark preference