body {
   font-family: 'Helvetica Neue', Arial, sans-serif;
   background: #f6f8fa;
   color: #333;
   display: flex;
   justify-content: center;
   align-items: center;
   height: 100vh;
   margin: 0;
}

.container {
   background: #fff;
   padding: 40px;
   border-radius: 12px;
   box-shadow: 0 4px 12px rgba(0,0,0,0.1);
   width: 100%;
   max-width: 400px;
   text-align: center;
}

h1 {
   font-size: 24px;
   margin-bottom: 20px;
   color: #2c3e50;
}

form {
   margin-top: 20px;
}

input[type="email"] {
   width: 100%;
   padding: 12px;
   border: 1px solid #ccc;
   border-radius: 8px;
   font-size: 16px;
   margin-bottom: 20px;
   box-sizing: border-box;
}

button {
   background-color: #007bff;
   color: white;
   border: none;
   padding: 14px;
   border-radius: 8px;
   cursor: pointer;
   font-size: 16px;
   transition: background-color 0.3s ease;
   width: 100%; /* ← 横いっぱいに広げる */
   font-weight: bold;
   letter-spacing: 1px;
   box-shadow: 0 4px 10px rgba(0, 123, 255, 0.3); /* 軽くシャドウで立体感 */
}

button:hover {
   background-color: #0056b3;
   box-shadow: 0 6px 14px rgba(0, 86, 179, 0.4);
}

p {
   margin-bottom: 16px;
   color: #2d3436;
}

a {
   display: inline-block;
   margin-top: 20px;
   font-size: 14px;
   color: #3498db;
   text-decoration: none;
}

a:hover {
   text-decoration: underline;
}