Better indentation.

app/templates/login.html

@@ -7,7 +7,7 @@ You're logged in already!
 <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" />
 <style>
   
-.container{
+  .container{
       background-color: #FFFFFF;
       width: 400px;
       height: 500px;
@@ -15,18 +15,18 @@ You're logged in already!
       border-radius: 1.5em;
       box-shadow: 0px 11px 35px 2px rgba(0, 0, 0, 0.14);
       
-}
+  }
 
-.signin-heading{
+  .signin-heading{
       padding-top: 5px;
       color: #8C55AA;
       font-family: 'Ubuntu', sans-serif;
       font-weight: bold;
       font-size: 23px;
       text-align: center;
-}
+  }
 
-.username, .email, .password, .re-password{
+  .username, .email, .password, .re-password{
       width: 76%;
       color: rgb(38, 50, 56);
       font-weight: 700;
@@ -44,9 +44,9 @@ You're logged in already!
       text-align: center;
       margin-bottom: 27px;
       font-family: 'Ubuntu', sans-serif;
-}
+  }
 
-.btn{
+  .btn{
       width: 50%;
       border: none;
       border-radius: 20px;
@@ -56,34 +56,34 @@ You're logged in already!
       margin-left: 90px;
       padding: 10px 20px;
       
-}
+  }
 
-.btn:hover{
+  .btn:hover{
 
       background: #8C55AA;
       transition: .5s;
       cursor: pointer;
       color: #fff;
-}
+  }
 
 
-.signup{
+  .signup{
       display: flex;
       justify-content: center;
       align-items: center;
-}
+  }
 
-ul{
+  ul{
       position: absolute;
       display: flex;
       left: 65%;
       
-}
+  }
 
-li{
+  li{
       padding: 10px;
       margin: 10px;  
-}
+  }
 
   a{
       text-decoration: none;
@@ -91,36 +91,36 @@ li{
       font-weight: bold;
       font-family: 'ink free';
       
-}
+  }
 
-.main_menu a{
+  .main_menu a{
       color: #fff;
       font-size: 300;
-}
+  }
 
-li :hover{
+  li :hover{
       color: #8C55AA;
       transition: .5s;
-}
+  }
 
-h1{
+  h1{
       font-family: 'ink free';
 
-}
+  }
 
-.main_menu h1{
+  .main_menu h1{
       color: #fff;
-}
+  }
 
 
-    </style>
+</style>
 
-    <div class="container">
+<div class="container">
   <section class="signin-heading">
     <h1>Sign In</h1>
   </section>
 
-<form action="/login" method="POST">
+  <form action="/login" method="POST">
     
     <input type="text" placeholder="用户名" class="username" name="username" required>
 
@@ -128,9 +128,9 @@ h1{
 
     <button type="submit" class="btn">登录</button>
 
-</form>
+  </form>
 
   <a href="/signup" class="signup">注册</a>
-{% endif %}
-{% endblock %}
+  {% endif %}
+  {% endblock %}