flarum.css: stronger overrides for serif body, hero, post structure

- Force serif on body/post/composer with broader, !important selectors
  to beat Flarum default cascade
- Hero + DiscussionHero: 2px text-colored bottom rule, larger title,
  italic serif subtitle for a present masthead
- Tag pill (e.g. "General") restyled: accent text on paper, sharp
  corners, mono caps, weighted
- Post divider darker; first post gets a top border for symmetry
- Avatar greyscale softened (30% instead of 80%) so identity reads
  without going washed-out

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

static/flarum.css

@@ -21,15 +21,34 @@
 
 /* ------------------------------------------------------------------------
    Body — paper background, serif body, editorial
+   Aggressive: force serif everywhere, then re-override mono/display zones
    ------------------------------------------------------------------------ */
+html, body, .App, .App-content, .container, .IndexPage, .DiscussionPage,
+.SettingsPage, .UserPage, .NotificationsPage, .Search-results,
+p, li, div, span, td, blockquote, .fa, em, strong {
+  font-family: var(--ob-serif) !important;
+}
+
 html, body, .App {
   background: var(--ob-bg) !important;
   color: var(--ob-text) !important;
-  font-family: var(--ob-serif) !important;
   font-size: 16.5px !important;
   line-height: 1.55 !important;
 }
 
+/* Form fields — serif for prose, sans for short controls */
+textarea, .Composer textarea, .Composer-body, .Composer-body *,
+.TextEditor, .TextEditor textarea, .ComposerBody-textarea,
+.RichEditor, .Post-body, .Post-body * {
+  font-family: var(--ob-serif) !important;
+  font-size: 1.02rem !important;
+  line-height: 1.55 !important;
+}
+
+input, select, .FormControl, .Search-input {
+  font-family: var(--ob-sans) !important;
+}
+
 /* Headlines — display sans */
 h1, h2, h3, h4, h5,
 .DiscussionListItem-title,
@@ -93,14 +112,57 @@ h1, h2, h3, h4, h5,
   text-transform: none !important;
 }
 
-.Hero {
+.Hero, .IndexPage .Hero {
   background: var(--ob-bg-2) !important;
   color: var(--ob-text) !important;
-  border-bottom: 1px solid var(--ob-border) !important;
+  border-bottom: 2px solid var(--ob-text) !important;
   text-shadow: none !important;
+  padding: 2.5rem 1rem !important;
+}
+.Hero-title {
+  color: var(--ob-text) !important;
+  font-size: 2rem !important;
+  font-weight: 700 !important;
+  letter-spacing: -0.015em !important;
+}
+.Hero-subtitle {
+  color: var(--ob-muted) !important;
+  font-style: italic;
+  font-family: var(--ob-serif) !important;
+  font-size: 1.1rem !important;
+  margin-top: 0.4rem !important;
+}
+
+/* Discussion page hero (when viewing a thread) — more present */
+.DiscussionHero {
+  background: var(--ob-bg-2) !important;
+  border-bottom: 2px solid var(--ob-text) !important;
+  box-shadow: none !important;
+  padding: 1.8rem 1rem !important;
+}
+.DiscussionHero-title {
+  color: var(--ob-text) !important;
+  font-size: 1.8rem !important;
+  font-weight: 700 !important;
+  letter-spacing: -0.015em !important;
+}
+
+/* Tag badge above title (e.g. "General") — pill but sharper */
+.DiscussionHero .TagsLabel,
+.DiscussionHero .TagLabel {
+  display: inline-block;
+  background: var(--ob-bg) !important;
+  border: 1px solid var(--ob-border) !important;
+  color: var(--ob-accent) !important;
+  text-transform: uppercase;
+  font-family: var(--ob-sans) !important;
+  font-size: 0.72rem !important;
+  font-weight: 600 !important;
+  letter-spacing: 0.06em !important;
+  padding: 0.2rem 0.55rem !important;
+  border-radius: 0 !important;
+  margin-bottom: 0.6rem !important;
 }
-.Hero-title { color: var(--ob-text) !important; }
-.Hero-subtitle { color: var(--ob-muted) !important; font-style: italic; font-family: var(--ob-serif) !important; }
 
 /* ------------------------------------------------------------------------
    Discussion list — editorial entries, no cards
@@ -142,14 +204,15 @@ h1, h2, h3, h4, h5,
   padding: 0.15rem 0.4rem !important;
 }
 
-/* Avatar — soften (greyscale until hover, like the website) */
+/* Avatar — squared, lightly desaturated, full color on hover */
 .Avatar {
   border-radius: 0 !important;
-  filter: grayscale(80%);
+  filter: grayscale(30%) contrast(0.95);
   transition: filter 0.3s ease;
 }
+.Avatar:hover,
 .DiscussionListItem:hover .Avatar,
-.Post:hover .Avatar { filter: grayscale(0%); }
+.Post:hover .Avatar { filter: grayscale(0%) contrast(1); }
 
 /* ------------------------------------------------------------------------
    Tags
@@ -256,9 +319,23 @@ a:hover { color: var(--ob-accent); border-bottom-color: var(--ob-accent); }
 
 .Post {
   border-bottom: 1px solid var(--ob-border) !important;
-  padding: 1rem 0 !important;
+  padding: 1.5rem 0 !important;
+}
+.Post:first-child { border-top: 1px solid var(--ob-border) !important; }
+.Post-header,
+.Post .PostUser,
+.Post .username {
+  font-family: var(--ob-mono) !important;
+  font-size: 0.85rem !important;
+  color: var(--ob-muted) !important;
+  font-weight: 500;
+}
+.Post .username { color: var(--ob-text) !important; }
+.Post .PostMeta time,
+.Post .Post-header time {
+  font-family: var(--ob-mono) !important;
+  color: var(--ob-muted) !important;
 }
-.Post-header { font-family: var(--ob-mono) !important; font-size: 0.85rem !important; color: var(--ob-muted) !important; }
 .Post-body {
   font-family: var(--ob-serif) !important;
   font-size: 1.02rem !important;