diff --git a/app.py b/app.py
index 934b302..7f58eb2 100644
--- a/app.py
+++ b/app.py
@@ -1,4 +1,6 @@
-from flask import Flask, render_template, redirect, request, url_for
+from functools import wraps
+
+from flask import Flask, render_template, redirect, request, url_for, session, flash
 from flask_sqlalchemy import SQLAlchemy
 from werkzeug.security import generate_password_hash, check_password_hash
 
@@ -19,6 +21,16 @@ with app.app_context():
     db.create_all()
 
 
+def login_required(view_func):
+    @wraps(view_func)
+    def wrapped(*args, **kwargs):
+        if 'user_id' not in session:
+            flash('Please sign in to view that page.')
+            return redirect(url_for('signin'))
+        return view_func(*args, **kwargs)
+    return wrapped
+
+
 @app.route('/submit-form', methods=['POST'])
 def handle_submission():
     form_username = request.form.get('username')
@@ -41,21 +53,21 @@ def handle_submission():
 
 
 @app.route('/users')
+@login_required
 def view_users():
     all_users = User.query.all()
-    
 
     html_output = "<h2>Registered Accounts</h2><table border='1' cellpadding='10'>"
     html_output += "<tr><th>ID</th><th>Username</th><th>Email</th></tr>"
-    
+
     for user in all_users:
-        html_output += f"<tr><td>{user.id}</td><td>{user.username}</td><td>{user.email}</td><td>{user.password_hash}</td></tr>"
-        
+        html_output += f"<tr><td>{user.id}</td><td>{user.username}</td><td>{user.email}</td></tr>"
+
     html_output += "</table>"
-    
+
     if not all_users:
         return "<h3>No accounts found in the database yet.</h3>"
-        
+
     return html_output
 
 
@@ -71,15 +83,36 @@ def bivariate():
 def about():
     return render_template('about.html')
 
-@app.route('/signin')
+@app.route('/signin', methods=['GET', 'POST'])
 def signin():
+    if request.method == 'POST':
+        form_username = request.form.get('username')
+        form_password = request.form.get('password')
+
+        user = User.query.filter_by(username=form_username).first()
+
+        if user is None or not check_password_hash(user.password_hash, form_password):
+            flash('Incorrect username or password.')
+            return render_template('signin.html'), 401
+
+        session['user_id'] = user.id
+        session['username'] = user.username
+        return redirect(url_for('home'))
+
     return render_template('signin.html')
 
+
+@app.route('/logout')
+def logout():
+    session.clear()
+    return redirect(url_for('home'))
+
 @app.route('/signup')
 def signup():
     return render_template('signup.html')
 
 @app.route('/all_users')
+@login_required
 def all_users():
     return render_template('all_users.html')
 
diff --git a/instance/accounts.db b/instance/accounts.db
index ed5a8aa..a120199 100644
Binary files a/instance/accounts.db and b/instance/accounts.db differ
diff --git a/static/style.css b/static/style.css
index b05b885..9c8f6d6 100644
--- a/static/style.css
+++ b/static/style.css
@@ -62,4 +62,18 @@ image {
   border-color: black;
   border-width: 2px;
   border-style: groove;
+}
+
+.flash-messages {
+  list-style-type: none;
+  margin: 0 0 16px 0;
+  padding: 0;
+}
+
+.flash-messages li {
+  background-color: #fee2e2;
+  color: #991b1b;
+  padding: 10px 14px;
+  border-radius: 4px;
+  margin-bottom: 8px;
 }
\ No newline at end of file
diff --git a/templates/base.html b/templates/base.html
index e3f45c9..b970225 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -9,11 +9,15 @@
 <body>
     <ul class="navbar">
         <li><a href="{{ url_for('home') }}">Home</a></li>
-        <li><a href="{{ url_for('bivariate') }}">Bivariate Data</a></li>
         <li><a href="{{ url_for('about') }}">About</a></li>
-        <li><a href="{{ url_for('all_users') }}">all_users</a></li>
+        {% if session.user_id %}
+        <li><a href="{{ url_for('bivariate') }}">Bivariate Data</a></li>
+        <li style="margin-left: auto; color: white; margin-top: 14px; margin-left: 900px;">Hi, {{ session.username }}</li>
+        <li style="margin-left: 20px;"><a href="{{ url_for('logout') }}">Sign Out</a></li>
+        {% else %}
         <li style="margin-left: auto;"><a href="{{ url_for('signup') }}">Sign Up</a></li>
         <li style="margin-left:0px"><a href="{{ url_for('signin') }}">Sign In</a></li>
+        {% endif %}
     </ul>
     <main>
         {% block content %}{% endblock %}
diff --git a/templates/index.html b/templates/index.html
index 5bc9b8c..9ec8cdd 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -5,6 +5,8 @@
 
     <h1>homepage for math website wow</h1>
 
+    <h2>If you want to access the math topics on this website you must be signed into a account</h2>
+
 
 </div>
 
diff --git a/templates/signin.html b/templates/signin.html
index ec9094b..8b14a56 100644
--- a/templates/signin.html
+++ b/templates/signin.html
@@ -1,13 +1,27 @@
 {% extends 'base.html' %}
 
 {% block content %}
-<head>
-    <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <link rel="stylesheet" href="style.css">
-</head>
-<body>
-    <h1>Sign in page with sql database</h1>
-</body>
+<h1>Sign in</h1>
 
+{% with messages = get_flashed_messages() %}
+  {% if messages %}
+    <ul class="flash-messages">
+      {% for message in messages %}
+        <li>{{ message }}</li>
+      {% endfor %}
+    </ul>
+  {% endif %}
+{% endwith %}
+
+<form action="{{ url_for('signin') }}" method="POST">
+    <label for="username">Username:</label>
+    <input type="text" id="username" name="username" required><br><br>
+
+    <label for="password">Password:</label>
+    <input type="password" id="password" name="password" required><br><br>
+
+    <button type="submit">Sign In</button>
+</form>
+
+<p>Don't have an account? <a href="{{ url_for('signup') }}">Sign up</a></p>
 {% endblock %}
\ No newline at end of file

ID	Username	Email
{user.id}	{user.username}	{user.email}	{user.password_hash}
{user.id}	{user.username}	{user.email}