/* 基础样式 */
body {
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
    min-height: 100vh;
    margin: 0;
    padding: 0;
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    position: relative;
    display: flex;
    flex-direction: column;
}

/* 半透明遮罩 */
body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(255, 255, 255, 0.85);
    z-index: -1;
}

/* 登录容器 */
.login-container {
    max-width: 800px;
    margin: 30px auto;
    padding: 0 20px;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

/* 登录框 */
.login-box {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    padding: 30px;
    box-shadow: 8px 8px 16px rgba(0,0,0,0.1);
    margin: 30px 0;
}

/* 标题 */
.login-box h1 {
    color: #4a6baf;
    text-align: center;
    margin-bottom: 30px;
    font-size: 28px;
}

/* 表单组 */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #4a6baf;
    font-weight: 500;
    font-size: 16px;
}

/* 输入框 */
.form-group input[type="password"] {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s;
}

.form-group input[type="password"]:focus {
    border-color: #4a8cff;
    box-shadow: 0 0 0 3px rgba(74, 140, 255, 0.2);
    outline: none;
}

/* 按钮 */
.btn {
    width: 100%;
    padding: 12px;
    background: linear-gradient(135deg, #4a8cff, #3a7bef);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 3px 3px 6px rgba(0,0,0,0.1);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 5px 5px 10px rgba(0,0,0,0.15);
    background: linear-gradient(135deg, #3a7bef, #2a6bdf);
}

/* 提示框 */
.alert {
    padding: 15px;
    margin-bottom: 20px;
    border-radius: 8px;
    font-size: 14px;
    display: none;
}

.alert-error {
    background-color: #ffebee;
    color: #ff4757;
    border: 1px solid #ffcdd2;
}

.alert-success {
    background-color: #e8f5e9;
    color: #2e7d32;
    border: 1px solid #c8e6c9;
}

/* 加载动画 */
.loader {
    border: 3px solid #f3f3f3;
    border-top: 3px solid #4a8cff;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    animation: spin 1s linear infinite;
    display: none;
    margin: 0 auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .login-container {
        padding: 0 15px;
    }
    
    .login-box {
        padding: 20px;
    }
    
    .login-box h1 {
        font-size: 24px;
    }
}