capsite/potluck: plain style after kmjn.org's "Plain HTML with a few bureaucratic gestures"

https://www.kmjn.org/notes/modern_plain_html.html and its stylesheet:
system fonts (Verdana; no Google webfonts), one 800px column,
line-height 1.35, links in the text color with a dotted underline, no
rounding, shadows, or tracking; the header is plain, not sticky glass.
Token overrides live in theme.css; per-page scoped styles unchanged.

Generated-by: Claude Opus 5.5

potluck/src/styles/theme.css

@@ -11,20 +11,50 @@
   changes light and dark mode at once; use light-dark(<light>, <dark>)
   to set different values per mode.
 
-  Webfonts are loaded in astro.config.mjs (--font-body, --font-mono).
-  Swap the loaded font there; use overrides here for system fonts or a
-  separate heading face.
-
-  Example:
-
-  :root {
-    --color-brand: light-dark(#0f766e, #2dd4bf);
-    --font-heading: "Iowan Old Style", Georgia, serif;
-    --radius: 8px;
-  }
+  potluck's look: plain HTML with a few bureaucratic gestures, after
+  https://www.kmjn.org/notes/modern_plain_html.html and its stylesheet
+  (https://www.kmjn.org/notes/style.css) -- system fonts (no webfonts;
+  astro.config.mjs loads none), one ~800px column, black links with a
+  dotted underline, no rounding, shadows, or tracking.
 */
 
 :root {
+	--font-body: verdana, sans-serif;
+	--font-mono: monospace;
+
+	--color-brand: var(--color-text);
+	--color-brand-hover: var(--color-text);
+	--color-on-brand: var(--color-bg);
+
+	--font-weight-heading: bold;
+	--font-weight-display: bold;
+	--tracking-tight: normal;
+	--tracking-snug: normal;
+	--leading-normal: 1.35;
+	--leading-relaxed: 1.35;
+
+	--content-width: 800px;
+	--wide-width: 800px;
+
+	--radius: 0;
+	--radius-lg: 0;
+	--shadow-sm: none;
+	--shadow-lg: none;
+}
+
+body {
+	-webkit-font-smoothing: auto;
+	-moz-osx-font-smoothing: auto;
+}
+
+a:where(:not([class*="emdash"]):not([class*="ec-"])) {
+	color: inherit;
+	border-bottom: 1px dotted;
+	overflow-wrap: break-word;
+}
+
+a:where(:not([class*="emdash"]):not([class*="ec-"])):hover {
+	border-bottom-style: solid;
 }
 
 /* Keep the signed-in Admin link separated from the primary navigation. */