Fix platform language links and contact button style

- Fix language prefix in platforms list links (/fr/platforms/macos/ instead of /platforms/macos/fr)
- Contact submit button: use explicit Tailwind classes instead of btn-primary

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: thooams

layouts/contact/list.html

@@ -34,7 +34,7 @@ <h1 class="text-3xl font-bold mb-3">{{ i18n "contact_title" }}</h1>
       <!-- Honeypot anti-spam -->
       <input type="text" name="_honeypot" style="display:none" tabindex="-1" autocomplete="off" />
 
-      <button type="submit" class="btn btn-primary w-full mt-2">
+      <button type="submit" class="btn bg-transparent border border-primary text-primary hover:bg-primary hover:text-primary-content w-full mt-2">
         {{ i18n "contact_send" }}
       </button>
     </form>

layouts/platforms/list.html

@@ -19,7 +19,7 @@ <h1 class="text-4xl md:text-5xl font-bold mb-4">{{ i18n "available_on" }}</h1>
       <div class="grid md:grid-cols-2 lg:grid-cols-4 gap-6 max-w-6xl mx-auto">
         {{ $platforms := $.Site.Data.platforms.platforms }}
         {{ range $platforms }}
-        <a href="{{ $.Site.BaseURL | strings.TrimSuffix "/" }}/platforms/{{ .slug }}{{ if ne $.Page.Lang "en" }}/{{ $.Page.Lang }}{{ end }}" class="group">
+        <a href="{{ $.Site.BaseURL | strings.TrimSuffix "/" }}{{ $.Site.LanguagePrefix }}/platforms/{{ .slug }}/" class="group">
           <div class="card bg-base-200 hover:bg-base-300 transition-all duration-300 h-full shadow-md hover:shadow-xl hover:-translate-y-1">
             <div class="card-body">
               <div class="text-4xl mb-4">