static/style.css: specify post divider colour

static/style.css

@@ -45,6 +45,11 @@ code {
     background: var(--faint_foreground);
 }
 
+/* post divider */
+.post:not(:last-of-type) {
+    border-bottom: 1px solid var(--bg_statusline1);
+}
+
 /* note: grey0 is actually fg0 with 0.5 opacity over bg0, so the below footer css has no effect. however, i've decided
  * to write it this way because i prefer to not use opacity to create colours when possible, instead setting
  * full-opacity explicit/unmodified colours. opacity is still used to create the dimmer hr in the footer.