fix: replace 'Xamxam' with 'Posterg' in public nav header

TODO.md

@@ -1,6 +1,7 @@
 # TODO
 
 ## Done
+- [x] Fix nav logo: revert to "Xamxam", apply display font (Combined), step-2 size, letter-spacing, text-shadow via .nav-logo class
 - [x] Bump all font sizes ~10% across all CSS files (admin, system, search, main, apropos, common, tfe)
 - [x] Migrate to utopia fluid type scale (--step--2 → --step-5) and space scale (--space-3xs → --space-3xl) across all CSS files
 - [x] Split search logic into search.php

public/assets/css/common.css

@@ -91,6 +91,16 @@ body > header nav {
   justify-content: space-between;
 }
 
+.nav-logo {
+  font-family: var(--font-display);
+  font-size: var(--step-2);
+  letter-spacing: 0.12em;
+  text-transform: uppercase;
+  color: var(--accent-foreground);
+  text-decoration: none;
+  text-shadow: 0 0 16px var(--header-shadow-strong), 0 0 32px var(--header-shadow-soft);
+}
+
 .nav-left {
   display: flex;
   align-items: center;

templates/header.php

@@ -36,7 +36,7 @@ $_thesisId     = $_GET['id'] ?? null;
 
     <nav aria-label="Navigation principale">
         <div class="nav-left">
-            <a href="/index.php">Xamxam</a>
+            <a href="/index.php" class="nav-logo">Xamxam</a>
             <ul class="nav-left-links">
                 <li>
                     <a href="/repertoire.php"