* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: "Microsoft YaHei", sans-serif;
        }
        body {
            min-width: 320px;
            background: #f7f7f7;
        }
        /* 顶部导航栏 - 保持原有尺寸不变 */
        .header {
            background: #fff;
            border-bottom: 1px solid #eee;
            padding: 0 100px; /* 关键修改：去掉上下内边距，避免高度增加 */
            height: 60px; /* 明确设置header高度，确保尺寸固定 */
            display: flex;
            align-items: center;
            justify-content: space-between;
        }
        .logo {
            display: flex;
            align-items: center;
            gap: 8px;
            height: 100%; /* 让logo容器继承header高度 */
        }
        .logo img {
            height: 100%; /* 关键修改：图片高度100%继承logo容器 */
            width: auto; /* 宽度自动适应，保持图片比例 */
            object-fit: contain; /* 确保图片完整显示，不拉伸变形 */
        }
        .logo-text {
            font-size: 24px;
            font-weight: bold;
            color: #00b359;
        }
        .nav-links {
            display: flex;
            gap: 40px;
        }
        .nav-links a {
            text-decoration: none;
            color: #333;
            font-size: 16px;
            transition: color 0.3s;
        }
        .nav-links a:hover {
            color: #0078d7;
        }
        /* 蓝色背景区 */
        .hero {
            background: linear-gradient(135deg, #2196f3 0%, #42a5f5 100%);
            padding: 20px 20px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            position: relative;
            overflow: hidden;
        }
        /* 背景方块装饰 */
        .hero::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-image: 
                linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px),
                linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
            background-size: 120px 120px;
            pointer-events: none;
        }
        .hero-title {
            font-size: 32px;
            color: #fff;
            margin-bottom: 20px;
            z-index: 1;
        }
        /* 登录表单 */
        .login-box {
            background: #fff;
            width: 100%;
            max-width: 420px;
            padding: 30px;
            border-radius: 8px;
            box-shadow: 0 4px 20px rgba(0,0,0,0.1);
            z-index: 1;
        }
        .form-item {
            margin-bottom: 15px;
        }
        .form-item input {
            width: 100%;
            height: 50px;
            padding: 0 15px;
            border: 1px solid #e0e0e0;
            border-radius: 4px;
            font-size: 16px;
            background: #f0f0f0;
            /* 核心修改：去掉焦点黑框 */
            outline: none;
        }
        .form-item input::placeholder {
            color: #999;
        }
        /* 可选：添加自定义焦点样式（更友好） */
        .form-item input:focus {
            border-color: #2196f3;
            background: #fff;
        }
        /* 按钮样式修改：去掉按钮组，登录按钮占满整行 */
        .btn-login {
            width: 100%;
            height: 45px;
            border: none;
            border-radius: 4px;
            font-size: 16px;
            cursor: pointer;
            transition: all 0.3s;
            background: #2196f3;
            color: #fff;
            /* 按钮也去掉焦点框 */
            outline: none;
            margin-top: 15px;
        }
        .btn-login:hover {
            background: #1976d2;
        }

        .copyright {
            text-align: center;
            padding: 15px;
            color: #666;
            font-size: 12px;
            border-top: 1px solid #eee;
            margin-top: 20px;
        }
        /* 响应式适配 */
        @media (max-width: 768px) {
            .header {
                flex-direction: column;
                gap: 0; /* 去掉gap避免高度增加 */
                padding: 10px 15px;
                height: auto; /* 移动端高度自适应 */
            }
            .logo {
                margin-bottom: 10px; /* 移动端增加底部间距 */
            }
            .logo img {
                max-height: 40px; /* 移动端限制图片最大高度 */
            }
            .nav-links {
                gap: 20px;
                margin-bottom: 10px;
            }
            .hero-title {
                font-size: 24px;
            }
            .login-box {
                padding: 20px;
            }
        }