admin/add: add ?mode=student toggle — hides admin header, keeps auth

TODO.md

@@ -7,3 +7,10 @@
 - [x] Use `<fieldset>` for danger zones (semantic, with `<legend>` instead of `<div>`)
 - [x] Update CSS: new `.param-*` classes for flat semantic layout
 - [x] Exclude parametres sections from generic `.admin-body main > section` card styling via `aria-labelledby` prefix
+
+## Add TFE: admin/student mode toggle
+- [x] Add `?mode=student` query param to same add.php page
+- [x] Student mode: no admin header/nav, just the form with a back-link
+- [x] Admin mode: full admin header/nav, with "Mode étudiant ↗" toggle link (opens in new tab)
+- [x] Auth guard stays the same — still requires admin login
+- [x] Add `.student-body`, `.thesis-add-header`, `.mode-toggle`, `.form-footer` CSS

public/admin/add.php

@@ -8,6 +8,7 @@ if (empty($_SESSION["csrf_token"])) {
 }
 
 $pageTitle = "Ajouter un TFE";
+$studentMode = isset($_GET['mode']) && $_GET['mode'] === 'student';
 
 require_once __DIR__ . '/../../src/ThesisCreateController.php';
 
@@ -47,11 +48,27 @@ function wasSelected($key, $value) {
     return $formData[$key] == $value;
 }
 ?>
-<?php $isAdmin = true; $bodyClass = 'admin-body'; require_once APP_ROOT . '/templates/head.php'; ?>
-    <?php include APP_ROOT . '/templates/header.php'; ?>
+<?php
+if ($studentMode) {
+    $bodyClass = 'student-body';
+    require_once APP_ROOT . '/templates/head.php';
+} else {
+    $isAdmin = true;
+    $bodyClass = 'admin-body';
+    require_once APP_ROOT . '/templates/head.php';
+    include APP_ROOT . '/templates/header.php';
+}
+?>
 
 <main id="main-content">
-    <h1>Ajouter un TFE</h1>
+    <div class="thesis-add-header">
+        <h1>Ajouter un TFE</h1>
+        <?php if (!$studentMode): ?>
+        <a href="?mode=student" class="mode-toggle" target="_blank" rel="noopener">Mode étudiant ↗</a>
+        <?php else: ?>
+        <a href="?mode=admin" class="mode-toggle mode-toggle--back">← Retour admin</a>
+        <?php endif; ?>
+    </div>
 
     <?php include APP_ROOT . '/templates/partials/flash-messages.php'; ?>
 
@@ -135,8 +152,8 @@ function wasSelected($key, $value) {
             include APP_ROOT . '/templates/partials/form/select-field.php';
         ?>
 
-        <div class="admin-form-footer">
-            <button type="submit" name="go" class="admin-btn">Soumettre</button>
+        <div class="form-footer">
+            <button type="submit" name="go">Soumettre</button>
         </div>
     </form>
 </main>

public/assets/css/admin.css

@@ -1683,3 +1683,72 @@
     flex-direction: column;
     gap: var(--space-3xs);
 }
+
+/* ── Student mode & toggle ──────────────────────────────────────────────────── */
+.student-body header {
+    display: none;
+}
+
+.student-body main {
+    max-width: 720px;
+}
+
+.thesis-add-header {
+    display: flex;
+    align-items: baseline;
+    justify-content: space-between;
+    gap: var(--space-m);
+    margin-bottom: var(--space-m);
+    border-bottom: 1px solid var(--border-primary);
+    padding-bottom: var(--space-xs);
+}
+
+.thesis-add-header h1 {
+    margin: 0;
+    font-size: var(--step-1);
+    font-weight: 600;
+    letter-spacing: 0.06em;
+    text-transform: uppercase;
+}
+
+.mode-toggle {
+    font-size: var(--step--1);
+    color: var(--text-secondary);
+    text-decoration: none;
+    white-space: nowrap;
+    border: 1px solid var(--border-primary);
+    border-radius: 3px;
+    padding: var(--space-3xs) var(--space-xs);
+    transition: color 0.15s, border-color 0.15s;
+}
+
+.mode-toggle:hover {
+    color: var(--accent-primary);
+    border-color: var(--accent-primary);
+}
+
+.mode-toggle--back {
+    color: var(--accent-blue);
+    border-color: var(--blue-muted-border, var(--border-primary));
+}
+
+.form-footer {
+    margin-top: var(--space-l);
+}
+
+.form-footer button {
+    padding: var(--space-2xs) var(--space-l);
+    background: var(--accent-primary);
+    color: var(--accent-foreground);
+    border: none;
+    border-radius: 3px;
+    font-size: var(--step--1);
+    font-family: inherit;
+    cursor: pointer;
+    letter-spacing: 0.04em;
+    transition: background 0.15s;
+}
+
+.form-footer button:hover {
+    background: var(--accent-secondary);
+}