Fix: Add confirmation dialog before deleting subject and persist user…

css/index.css

@@ -5022,3 +5022,51 @@ body {
 .subject-sidebar-item:hover .delete-subject-btn {
   opacity: 1;
 }
+
+/* ============================================================
+   Custom Confirm Modal (used by Toast.confirm())
+   ============================================================ */
+
+.custom-confirm-backdrop {
+  position: fixed;
+  inset: 0;
+  background: rgba(0, 0, 0, 0.5);
+  z-index: 9999;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: 24px;
+}
+
+.custom-confirm-modal {
+  width: min(420px, 100%);
+  padding: 28px;
+}
+
+.modal-card {
+  background: var(--color-background-primary);
+  border: 1px solid var(--color-border-secondary);
+  border-radius: 16px;
+  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.2);
+}
+
+/* Animations */
+@keyframes fadeIn {
+  from { opacity: 0; }
+  to   { opacity: 1; }
+}
+
+@keyframes fadeOut {
+  from { opacity: 1; }
+  to   { opacity: 0; }
+}
+
+@keyframes slideUp {
+  from { opacity: 0; transform: translateY(24px) scale(0.97); }
+  to   { opacity: 1; transform: translateY(0)    scale(1);    }
+}
+
+@keyframes slideDown {
+  from { opacity: 1; transform: translateY(0)    scale(1);    }
+  to   { opacity: 0; transform: translateY(24px) scale(0.97); }
+}

database.js

@@ -5,6 +5,14 @@ const db = new sqlite3.Database(path.join(__dirname, 'studyplan.db'));
 
 function initDb() {
   db.serialize(() => {
+    // Users Table
+    db.run(`CREATE TABLE IF NOT EXISTS users (
+      id TEXT PRIMARY KEY,
+      email TEXT NOT NULL UNIQUE,
+      password TEXT NOT NULL,
+      created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+    )`);
+
     // Subjects Table
     db.run(`CREATE TABLE IF NOT EXISTS subjects (
       id TEXT PRIMARY KEY,

js/app.js

@@ -199,12 +199,21 @@ return `
 
   document.querySelectorAll('.delete-subject-btn')
   .forEach(btn => {
-    btn.addEventListener('click', (e) => {
+    btn.addEventListener('click', async (e) => {
       e.stopPropagation();
 
       const subjectId = btn.dataset.subjectId;
+      const subject = store.subjects.find(s => s.id === subjectId);
+      const subjectName = subject ? subject.name : 'this subject';
+
+      const confirmed = await Toast.confirm(
+        `Are you sure you want to delete "${subjectName}"? All associated tasks will also be permanently removed. This action cannot be undone.`
+      );
 
-      store.deleteSubject(subjectId);
+      if (confirmed) {
+        store.deleteSubject(subjectId);
+        Toast.show(`"${subjectName}" has been deleted.`, 'success');
+      }
     });
   });
 }

server.js

@@ -553,30 +553,36 @@ Text: "${text}"
   return res.json(tasks);
 });
 // ================= AUTH =================
-const users = {}; // Simple in-memory user store
+// Users are now stored in SQLite so they persist across server restarts
 
 app.post('/api/auth/signup', (req, res) => {
   const { email, password } = req.body;
   if (!email || !password) {
     return res.status(400).json({ error: 'Email and password required' });
   }
-  if (users[email]) {
-    return res.status(400).json({ error: 'User already exists' });
-  }
-  users[email] = { email, password };
-  res.json({ success: true, message: 'Account created successfully' });
+  db.get('SELECT * FROM users WHERE LOWER(email) = LOWER(?)', [email], (err, row) => {
+    if (err) return res.status(500).json({ error: err.message });
+    if (row) return res.status(400).json({ error: 'User already exists' });
+    const id = 'user_' + Date.now() + Math.random().toString(36).slice(2, 7);
+    db.run('INSERT INTO users (id, email, password) VALUES (?, ?, ?)', [id, email, password], function (insertErr) {
+      if (insertErr) return res.status(500).json({ error: insertErr.message });
+      res.json({ success: true, message: 'Account created successfully' });
+    });
+  });
 });
 
 app.post('/api/auth/login', (req, res) => {
   const { email, password } = req.body;
   if (!email || !password) {
     return res.status(400).json({ error: 'Email and password required' });
   }
-  const user = users[email];
-  if (!user || user.password !== password) {
-    return res.status(401).json({ error: 'Invalid email or password' });
-  }
-  res.json({ success: true, email: user.email });
+  db.get('SELECT * FROM users WHERE LOWER(email) = LOWER(?)', [email], (err, user) => {
+    if (err) return res.status(500).json({ error: err.message });
+    if (!user || user.password !== password) {
+      return res.status(401).json({ error: 'Invalid email or password' });
+    }
+    res.json({ success: true, email: user.email });
+  });
 });
 
 // Intentional test route for verifying server error page behavior.