/* 通用样式 */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f2f5;
    margin: 0;
    display: flex;
    justify-content: center;
    min-height: 100vh;
    align-items: center;
}

.container {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 400px;
}

h2 {
    color: #1a1a1a;
    text-align: center;
    margin-bottom: 1.5rem;
}

.form-section {
    margin-bottom: 30px;
    padding: 20px;
    background-color: #f9f9f9;
    border-radius: 5px;
}

.form-group {
    margin-bottom: 1rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    color: #333;
    font-weight: 500;
}

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

input[type="text"]:focus,
input[type="password"]:focus {
    border-color: #007bff;
    outline: none;
}

button {
    width: 100%;
    padding: 0.8rem;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

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

.alert {
    padding: 0.8rem;
    margin-bottom: 1rem;
    border-radius: 4px;
}

.alert-error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.text-center {
    text-align: center;
}

.mt-2 {
    margin-top: 1rem;
}

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

a:hover {
    text-decoration: underline;
}

.current-username {
    font-weight: bold;
    margin-bottom: 10px;
}