/* ===== 全局设计变量 ===== */
        :root {
            --primary: #2563eb;
            --primary-light: #eff6ff;
            --gray-light: #f3f4f6;
            --gray: #6b7280;
            --dark: #1f2937;
            --shadow: 0 2px 10px rgba(0,0,0,0.04);
            --shadow-hover: 0 8px 20px rgba(37,99,235,0.12);
            --radius: 16px;
            --radius-sm: 12px;
        }

        /* ===== 基础重置 ===== */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
        }

        body {
            background: linear-gradient(145deg, #f9fcff 0%, #f1f5f9 100%);
            color: var(--dark);
            line-height: 1.6;
            min-height: 100vh;
        }

        .container {
            max-width: 1300px;
            margin: 0 auto;
            padding: 0 1.5rem; /* 上下内边距归零，顶部无空隙 */
        }

        /* ===== 头部 (纯白底, 柔和阴影, 顶部无间距) ===== */
        .header-wrapper {
            background: #ffffff;
            border-radius: 0 0 40px 40px; /* 只保留底部圆角，顶部直角贴边 */
            padding: 0.6rem 2rem;
            margin: 0 0 2.5rem 0; /* 上边距归零 */
            box-shadow: var(--shadow);
            border: 1px solid rgba(0,0,0,0.02);
            border-top: none; /* 移除顶部边框线，更贴合 */
            position: sticky;
            top: 0;
            z-index: 999;
            backdrop-filter: blur(2px);
            transition: all 0.2s;
        }

        .header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: nowrap;
            gap: 1rem;
        }

        .logo {
            flex-shrink: 0;
        }

        .logo-img {
            height: 38px;
            width: auto;
            display: block;
        }

        /* 导航 */
        .nav {
            display: flex;
            align-items: center;
            justify-content: flex-end;
            position: relative;
        }

        .nav-menu {
            display: flex;
            align-items: center;
            gap: 0.2rem;
        }

        .nav a {
            color: #334155;
            text-decoration: none;
            font-weight: 500;
            font-size: 1rem;
            padding: 0.5rem 1.2rem;
            border-radius: 30px;
            transition: all 0.2s;
            white-space: nowrap;
        }

        .nav a:hover {
            color: var(--primary);
            background: var(--primary-light);
        }

        .nav a.active {
            color: white;
            background: var(--primary);
            font-weight: 500;
            box-shadow: 0 4px 10px rgba(37,99,235,0.3);
        }

        /* 汉堡菜单 */
        .nav-toggle {
            display: none;
            background: none;
            border: none;
            cursor: pointer;
            padding: 0.5rem;
            margin-left: 0.5rem;
            z-index: 101;
        }

        .hamburger {
            display: block;
            width: 24px;
            height: 2px;
            background: #334155;
            position: relative;
            transition: background 0.2s;
        }

        .hamburger::before,
        .hamburger::after {
            content: '';
            position: absolute;
            width: 100%;
            height: 2px;
            background: #334155;
            left: 0;
            transition: transform 0.3s;
        }

        .hamburger::before { top: -6px; }
        .hamburger::after { bottom: -6px; }

        .nav.active .hamburger {
            background: transparent;
        }

        .nav.active .hamburger::before {
            transform: rotate(45deg);
            top: 0;
        }

        .nav.active .hamburger::after {
            transform: rotate(-45deg);
            bottom: 0;
        }

        /* ===== 隐私徽章 ===== */
        .privacy-badge {
            background: var(--primary-light) !important;
            color: var(--primary) !important;
            border-radius: 40px;
            padding: 0.6rem 1.6rem !important;
            margin: 0 auto 2.5rem auto !important;
            max-width: fit-content;
            font-size: 0.95rem;
            display: flex;
            align-items: center;
            gap: 0.5rem;
            box-shadow: var(--shadow);
            border: 1px solid rgba(37,99,235,0.2);
            font-weight: 500;
        }
        .privacy-badge a {
            color: #2563eb;
            font-weight: 600;
            text-decoration: underline;
            margin-left: 4px;
        }

        .privacy-badge a:hover {
            color: #1d4ed8;
        }
        
        /* ===== 通用区块标题 ===== */
        .section-title {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1.8rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid rgba(0,0,0,0.03);
        }

        .section-title h2 {
            font-size: 1.5rem;
            font-weight: 600;
            color: var(--dark);
            letter-spacing: -0.3px;
            display: flex;
            align-items: center;
            gap: 0.3rem;
        }

        .section-title a {
            color: var(--primary);
            font-size: 0.95rem;
            font-weight: 500;
            display: inline-flex;
            align-items: center;
            gap: 0.4rem;
            background: rgba(37,99,235,0.08);
            padding: 0.4rem 1.2rem;
            border-radius: 30px;
            transition: all 0.2s;
            text-decoration: none;
        }

        .section-title a:hover {
            background: rgba(37,99,235,0.15);
            transform: translateX(3px);
        }

        /* ===== 工具网格 ===== */
        .tool-grid {
            display: grid;
            grid-template-columns: repeat(7, 1fr);
            gap: 1rem;
            margin-bottom: 4rem;
        }

        .tool-card {
            background: white;
            border-radius: var(--radius-sm);
            padding: 1.2rem 0.5rem;
            text-align: center;
            box-shadow: var(--shadow);
            transition: all 0.25s ease;
            border: 1px solid #ffffff50;
            text-decoration: none;
            color: var(--dark);
            display: flex;
            flex-direction: column;
            align-items: center;
            backdrop-filter: blur(2px);
        }

        .tool-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
            border-color: var(--primary-light);
            background: var(--primary-light);
        }

        .tool-emoji {
            font-size: 2.2rem;
            line-height: 1;
            margin-bottom: 0.3rem;
            display: block;
        }

        .tool-card span:last-child {
            font-size: 0.85rem;
            font-weight: 500;
            word-break: break-word;
            color: #1e293b;
        }

        /* ===== 博客卡片 ===== */
        .blog-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: 1.5rem;
            margin: 1.5rem 0 2.5rem;
        }

        .blog-card {
            background: white;
            border-radius: var(--radius-sm);
            padding: 1.5rem;
            box-shadow: var(--shadow);
            transition: all 0.25s ease;
            border: 1px solid #ecf3fa;
            text-decoration: none;
            color: inherit;
            display: flex;
            flex-direction: column;
            height: 100%;
        }

        .blog-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
            border-left: 4px solid var(--primary);
        }

        .blog-card h3 {
            font-size: 1.1rem;
            font-weight: 600;
            margin-bottom: 0.6rem;
            color: #0b1e33;
            line-height: 1.4;
        }

        .blog-card p {
            color: var(--gray);
            font-size: 0.9rem;
            margin-bottom: 1.2rem;
            flex: 1;
            line-height: 1.5;
            display: -webkit-box;
            -webkit-line-clamp: 3;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        .blog-meta {
            display: flex;
            justify-content: space-between;
            align-items: center;
            color: #5f6c84;
            font-size: 0.8rem;
            border-top: 1px dashed #dce5ef;
            padding-top: 0.8rem;
        }

        .blog-meta .date {
            display: flex;
            align-items: center;
            gap: 0.3rem;
        }

        .blog-meta .tag {
            background: var(--primary-light);
            color: var(--primary);
            padding: 0.2rem 1rem;
            border-radius: 30px;
            font-size: 0.7rem;
            font-weight: 600;
            letter-spacing: 0.3px;
        }

        /* ===== 友情链接 ===== */
        .friend-links {
            margin: 3rem 0 2rem;
            padding: 2rem 1.5rem;
            background: var(--gray-light);
            border-radius: var(--radius);
            text-align: center;
        }

        .friend-links-title {
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--dark);
            margin-bottom: 1.2rem;
        }

        .friend-links-grid {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 0.8rem 1.2rem;
        }

        .friend-links-grid a {
            color: var(--gray);
            text-decoration: none;
            font-size: 0.9rem;
            padding: 0.4rem 1rem;
            background: white;
            border-radius: 30px;
            transition: all 0.2s;
            box-shadow: 0 1px 3px rgba(0,0,0,0.02);
        }

        .friend-links-grid a:hover {
            color: var(--primary);
            background: var(--primary-light);
            transform: translateY(-2px);
        }

        /* ===== 页脚 ===== */
        .footer {
            text-align: center;
            padding: 2rem 0 1rem;
            border-top: 1px solid #d9e2ef;
            color: var(--gray);
            font-size: 0.9rem;
        }

        .footer a {
            color: var(--primary);
            text-decoration: none;
            margin: 0 0.3rem;
        }

        .footer a:hover {
            text-decoration: underline;
        }

        /* ===== 语言切换器样式 ===== */
        .lang-switch {
            display: flex;
            align-items: center;
            margin-left: 1.5rem;
            font-size: 0.9rem;
            background: #f1f5f9;
            border-radius: 30px;
            padding: 0.2rem;
        }
        
        .lang-switch a {
            text-decoration: none;
            padding: 0.3rem 0.8rem;
            border-radius: 30px;
            font-weight: 500;
            color: #334155;
            transition: all 0.2s;
            display: inline-block;
        }
        
        .lang-switch a.active-lang {
            background: #2563eb;
            color: white;
        }
        
        .header .nav {
            display: flex;
            align-items: center;
        }

        /* ===== 响应式优化 ===== */
        @media (max-width: 1100px) {
            .tool-grid {
                grid-template-columns: repeat(5, 1fr);
            }
        }

        @media (max-width: 900px) {
            .tool-grid {
                grid-template-columns: repeat(4, 1fr);
            }
        }

        @media (max-width: 768px) {
            .container { padding: 0 1rem; }

            .header-wrapper {
                padding: 0.5rem 1.2rem;
                border-radius: 0 0 30px 30px;
            }

            .nav-toggle {
                display: block;
            }

            /* 修复：默认隐藏手机端菜单 */
            .nav-menu {
                display: none;
                position: absolute;
                top: 48px;
                right: 0;
                left: auto;
                min-width: 200px;
                flex-direction: column;
                background: white;
                border-radius: 18px;
                box-shadow: 0 12px 30px rgba(0,0,0,0.15);
                padding: 0.8rem;
                border: 1px solid #edf2f7;
                z-index: 100;
            }

            .nav-menu a {
                width: 100%;
                text-align: left;
                padding: 0.7rem 1.2rem;
                white-space: normal;
            }

            .nav-menu a:not(:last-child) {
                border-bottom: 1px solid #f1f5f9;
            }

            /* 只有添加active类时才显示菜单 */
            .nav.active .nav-menu {
                display: flex;
            }

            .tool-grid {
                grid-template-columns: repeat(3, 1fr);
            }

            .lang-switch {
                margin: 0.5rem 0 0 0;
                align-self: flex-start;
            }
            
            .nav.active .nav-menu {
                display: flex;
                flex-direction: column;
                width: 100%;
            }
        }

        @media (max-width: 600px) {
            .tool-grid {
                grid-template-columns: repeat(2, 1fr);
            }

            .privacy-badge {
                font-size: 0.8rem;
                padding: 0.4rem 1.2rem !important;
            }

            .section-title h2 {
                font-size: 1.3rem;
            }
        }

        @media (max-width: 400px) {
            .tool-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        /* 保留广告位原有样式(透明无框) —— 与原设计一致 */
        .ad-banner {
            padding: 0;
            text-align: center;
            background: transparent;
            border: none;
            min-height: auto;
            display: block;
            backdrop-filter: none;
        }

        .ad-link {
            display: block;
            width: 100%;
            text-decoration: none;
        }

        .ad-image {
            width: 100%;
            height: auto;
            max-width: 100%;
            border-radius: 16px;
            display: block;
        }