* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.login-container {
    background: white;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    padding: 40px;
    width: 100%;
    max-width: 450px;
    text-align: center;
    margin: auto;
}

/* 移动端适配 */
@media (max-width: 768px) {
    body {
        padding: 10px;
        align-items: flex-start;
        padding-top: 40px;
    }
    
    .login-container {
        padding: 30px 20px;
        max-width: 100%;
        border-radius: 8px;
    }
    
    .logo img {
        max-width: 100px;
    }
    
    .system-name {
        font-size: 22px;
    }
    
    .login-btn {
        padding: 15px 20px;
        font-size: 15px;
    }
}

/* 超小屏幕适配 */
@media (max-width: 480px) {
    .login-container {
        padding: 25px 15px;
    }
    
    .logo img {
        max-width: 80px;
    }
    
    .system-name {
        font-size: 20px;
    }
    
    .system-desc {
        font-size: 13px;
    }
    
    .login-btn {
        padding: 12px 15px;
        font-size: 14px;
    }
}

/* 平板设备适配 */
@media (min-width: 769px) and (max-width: 1024px) {
    .login-container {
        max-width: 400px;
    }
}

/* 设备特定样式优化 */
.device-mobile .login-container {
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.device-mobile .login-btn {
    min-height: 50px;
}

.device-tablet .login-container {
    max-width: 500px;
}

.device-desktop .login-container {
    transition: transform 0.3s ease;
}

.device-desktop .login-container:hover {
    transform: translateY(-5px);
}

.logo {
    margin-bottom: 30px;
}

.logo img {
    max-width: 200px;
    height: auto;
}

.system-name {
    color: #2c3e50;
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 10px;
}

.system-desc {
    color: #7f8c8d;
    font-size: 14px;
    margin-bottom: 30px;
}

.login-options {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.login-btn {
    padding: 12px 20px;
    border: 2px solid #3498db;
    border-radius: 8px;
    background: white;
    color: #3498db;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.login-btn:hover {
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.login-btn.unified {
    border-color: #3498db;
    color: #3498db;
}

.login-btn.sms {
    border-color: #27ae60;
    color: #27ae60;
}

.login-btn.email {
    border-color: #e74c3c;
    color: #e74c3c;
}

.btn-icon {
    font-size: 18px;
}

.footer {
    margin-top: 30px;
    color: #95a5a6;
    font-size: 12px;
}