Fix nested list extra margin (picocss/pico#672).

Author: Amaury

CLAUDE.md

@@ -53,6 +53,7 @@ These µCSS rules exist to fix PicoCSS default behaviors:
 - `nav a { text-decoration: none }` — Remove underline on all nav links (PicoCSS hover underline)
 - `.table-bordered` border uses `color-mix()` blend for visible but lighter cell borders
 - Nav/header with `.bg-*` get a gradient via `color-mix(in oklch)` (same as hero)
+- `li ul, li ol { margin-bottom: 0 }` — Fix nested list extra margin (picocss/pico#672) — remove when fixed upstream
 - `nav details.dropdown { display: inline-block }` — Fix Firefox full-width nav dropdowns (picocss/pico#701) — remove when fixed upstream
 - PicoCSS sets `:where(table) { width: 100% }` — all tables are fullwidth by default, no `.table-fullwidth` class needed
 - PicoCSS `.outline` button style (3 colors) coexists with µCSS `.btn-outline` (11 colors) — different selectors, no conflict

css/mu.utilities.css

@@ -1,7 +1,15 @@
 /*
- * µCSS Utilities: Positioning
+ * µCSS Utilities
  */
 
+/* PicoCSS bugfix: nested lists have unwanted bottom margin (picocss/pico#672) — remove when fixed upstream */
+li ul,
+li ol {
+	margin-bottom: 0;
+}
+
+/* Positioning */
+
 .sticky-top {
 	position: sticky;
 	top: 0;