{% block body %}
{% if session['logged_in'] %}

You're logged in already!

{% else %}
<meta charset="utf-8" name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=0.5, maximum-scale=3.0, user-scalable=yes" />
<link rel="stylesheet" href="static/css/login_service.css">

<div class="container">

  <section class="signin-heading">
    <h1>Sign In</h1>
  </section>

  <form action="/login" method="POST">
    <input type="text" placeholder="用户名" class="username" name="username" required>
    <input type="password" placeholder="密码" class="password"  name="password" required>
    <button type="submit" class="btn">登录</button>
  </form>

</div>

<a href="/signup" class="signup">注册</a>

{% endif %}
{% endblock %}