/* 自定义搜索框样式 - 嵌入 .tel 内部 */
.search-form {
    display: flex;
    align-items: center;
    background: #fff;
    border: 1px solid #dcdfe6;
    border-radius: 32px;
    overflow: hidden;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    transition: all 0.2s;
}
.search-form:hover,
.search-form:focus-within {
    border-color: #c00;
    box-shadow: 0 0 0 2px rgba(204,0,0,0.1);
}
.search-input {
    flex: 1;
    border: none;
    padding: 8px 15px;
    font-size: 14px;
    outline: none;
    background: transparent;
    color: #333;
}
.search-input::placeholder {
    color: #b0b3b8;
    font-size: 13px;
}
.search-btn {
    background: #c00;
    border: none;
    color: #fff;
    font-size: 14px;
    padding: 0 18px;
    height: 36px;
    line-height: 36px;
    cursor: pointer;
    transition: background 0.2s;
    font-weight: normal;
    border-radius: 0 32px 32px 0;
    letter-spacing: 1px;
}
.search-btn:hover {
    background: #a00;
}

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

        body {
            background: #f0f4f8;
            font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
            line-height: 1.4;
            padding: 2rem 1.5rem;
            color: #1a2c3e;
        }

        /* 主容器 - 保留原 class 以兼容，但完全重构样式 */
        .twofenlei2 {
            max-width: 1400px;
            margin: 0 auto;
        }

        /* 一级分类网格布局 (自适应多列) */
        .category-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
            gap: 1.8rem;
        }

        /* 分类卡片 */
        .cat-card {
            background: #ffffff;
            border-radius: 24px;
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.03), 0 2px 6px rgba(0, 0, 0, 0.05);
            transition: all 0.2s ease;
            overflow: hidden;
            display: flex;
            flex-direction: column;
            border: 1px solid #e9edf2;
        }

        .cat-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 20px 30px -12px rgba(0, 0, 0, 0.12);
            border-color: #cfdee9;
        }

        /* 一级分类头部 */
        .primary-cat {
            background: #f9fafc;
            padding: 1.2rem 1.5rem;
            border-bottom: 2px solid #e2e8f0;
            transition: background 0.2s;
        }

        .primary-cat a {
            font-size: 1.35rem;
            font-weight: 600;
            letter-spacing: -0.01em;
            text-decoration: none;
            color: #005c8a;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            transition: color 0.2s;
        }

        .primary-cat a:hover {
            color: #003f5c;
            text-decoration: underline;
        }

        /* 装饰小标记 (替代原方括号，更美观) */
        .primary-icon {
            font-size: 1.5rem;
            font-weight: 500;
            opacity: 0.7;
            color: #2c7da0;
        }

        /* 二级分类区域 */
        .subcategory-area {
            padding: 1.2rem 1.5rem 1.5rem;
            flex: 1;
        }

        .sub-list {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
            gap: 0.7rem 1rem;
        }

        .sub-item {
            list-style: none;
        }

        .sub-item a {
            font-size: 0.9rem;
            text-decoration: none;
            color: #2c3e4e;
            background: #f8fafc;
            padding: 0.45rem 0.8rem;
            border-radius: 30px;
            display: inline-block;
            width: 100%;
            transition: all 0.2s;
            border: 1px solid #eef2f6;
            text-align: center;
            font-weight: 450;
        }

        .sub-item a:hover {
            background: #e6f0f9;
            color: #005c8a;
            border-color: #bdd8ec;
            transform: translateX(3px);
        }

        /* 无二级分类的占位优雅提示 */
        .no-sub {
            color: #859dae;
            font-size: 0.85rem;
            font-style: normal;
            background: #fefce8;
            padding: 0.6rem 1rem;
            border-radius: 40px;
            text-align: center;
            border: 1px dashed #cbdbe2;
            display: inline-block;
            width: 100%;
        }

        /* 针对气驱动器较多子项时，让子项排布紧凑但可读 */
        @media (max-width: 640px) {
            body {
                padding: 1.2rem;
            }
            .category-grid {
                gap: 1.2rem;
                grid-template-columns: 1fr;
            }
            .primary-cat a {
                font-size: 1.2rem;
            }
            .sub-list {
                grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
                gap: 0.6rem;
            }
            .sub-item a {
                font-size: 0.85rem;
                padding: 0.4rem 0.5rem;
            }
        }

        /* 自定义滚动条与辅助 */
        ::-webkit-scrollbar {
            width: 8px;
            height: 8px;
        }
        ::-webkit-scrollbar-track {
            background: #eef2f5;
            border-radius: 10px;
        }
        ::-webkit-scrollbar-thumb {
            background: #b9ccda;
            border-radius: 10px;
        }

        /* 页眉装饰 */
        .nav-header {
            margin-bottom: 2.2rem;
            text-align: left;
            border-left: 5px solid #0077b6;
            padding-left: 1.2rem;
        }
        .nav-header h2 {
            font-size: 1.9rem;
            font-weight: 600;
            color: #0a2b3b;
            letter-spacing: -0.3px;
        }
        .nav-header p {
            color: #4b6f86;
            margin-top: 0.4rem;
            font-size: 0.95rem;
        }

        /* 卡片脚标轻提示 */
        .badge-tip {
            display: inline-block;
            font-size: 0.7rem;
            background: #eef2fc;
            border-radius: 30px;
            padding: 0.2rem 0.6rem;
            margin-left: 0.6rem;
            color: #2c7a47;
            vertical-align: middle;
        }