/* 基础样式：适配手机和电脑 */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #f0f2f5;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.container {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    width: 90%;
    max-width: 350px;
    text-align: center;
}

h2 { color: #333; margin-bottom: 1.5rem; }

input {
    width: 100%;
    padding: 12px;
    margin: 8px 0;
    border: 1px solid #ddd;
    border-radius: 6px;
    box-sizing: border-box; /* 防止输入框超出边界 */
}

button {
    width: 100%;
    padding: 12px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    margin-top: 10px;
}

button:hover { background-color: #0056b3; }

#message { margin-top: 15px; font-size: 14px; color: #d9534f; }

a { color: #007bff; text-decoration: none; }