fix: CSP compliance for inline styles and scripts

css/styles.css

@@ -18,6 +18,11 @@
     border: 0 !important;
 }
 
+/* Masquage d'éléments (remplace les attributs style="display: none;" bloqués par la CSP) */
+.is-hidden {
+    display: none !important;
+}
+
 :root {
     --primary-red: #FF0000;
     --primary-green: #008000;
@@ -3576,3 +3581,38 @@ i.icon-mastodon,
     text-align: center;
     margin: 4px 0 10px;
 }
+
+/* Pages d'erreur (404.php / 500.php) */
+.error-page {
+    text-align: center;
+    padding: 80px 20px;
+}
+
+.error-page .error-code {
+    font-size: 4.5rem;
+    font-weight: bold;
+    line-height: 1;
+    color: var(--primary-red);
+    margin-bottom: 10px;
+}
+
+.error-page h1 {
+    margin-bottom: 15px;
+}
+
+.error-page > p:not(.error-code):not(.error-actions) {
+    max-width: 600px;
+    margin: 0 auto 25px;
+}
+
+.error-page .error-home-link {
+    display: inline-block;
+    padding: 10px 25px;
+    background-color: var(--primary-red);
+    color: #ffffff;
+    border-radius: 5px;
+}
+
+.error-page .error-home-link:hover {
+    opacity: 0.85;
+}