body::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-image: 
                url("/static/index/picture/Biochemical engineering industry.jpeg");
            opacity: 0.4;
            z-index: -1;
            background-size: cover;  /* 新增属性 */
            background-repeat: no-repeat;  /* 新增属性 */
        }

        .cs-container {
            max-width: 1230px;
            margin: 0 auto;
            background: rgba(255, 255, 255, 0.6);
            border-radius: 12px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
            overflow: hidden;
            padding: 30px;
            margin-bottom: 50px;
        }

        .cs-header {
            text-align: center;
            margin-bottom: 30px;
            padding-bottom: 20px;
            border-bottom: 1px solid #e0e7ff;
        }

        .cs-header h1 {
            color: #0056b3;
            font-size: 2.5rem;
            margin-bottom: 15px;
            font-weight: 700;
        }

        .cs-header p {
            color: #4a5568;
            font-size: 1.1rem;
            max-width: 800px;
            margin: 0 auto;
            line-height: 1.6;
        }

        .cs-tabs {
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 15px;
            margin-bottom: 30px;
        }

        .cs-tab {
            background: #edf2f7;
            border: none;
            padding: 15px 15px;
            border-radius: 8px;
            font-size: 1.1rem;
            font-weight: 600;
            color: #4a5568;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
        }

        .cs-tab:hover {
            background: #e2e8f0;
            transform: translateY(-2px);
        }

        .cs-tab.active {
            background: #007bff;
            color: white;
            box-shadow: 0 4px 10px rgba(0, 123, 255, 0.3);
        }

        .cs-content {
            display: none;
            animation: fadeIn 0.5s ease;
        }

        .cs-content.active {
            display: block;
        }

        .cs-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
            gap: 25px;
            margin-bottom: 40px;
        }

        .cs-card {
            background: white;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border-top: 4px solid #007bff;
        }

        .cs-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 25px rgba(0, 123, 255, 0.15);
        }

        .card-header {
            background: linear-gradient(135deg, #007bff 0%, #0056b3 100%);
            padding: 20px;
            color: white;
        }

        .card-header h3 {
            font-size: 1.4rem;
            margin-bottom: 8px;
        }

        .card-header p {
            font-size: 1rem;
            opacity: 0.9;
        }

        .card-body {
            padding: 25px;
        }

        .card-section {
            margin-bottom: 20px;
        }

        .card-section h4 {
            color: #2d3748;
            font-size: 1.1rem;
            margin-bottom: 10px;
            padding-bottom: 8px;
            border-bottom: 1px dashed #e2e8f0;
        }

        .card-section p {
            color: #4a5568;
            line-height: 1.6;
            margin-bottom: 8px;
        }

        .temp-range {
            display: inline-block;
            background: #fff5f5;
            color: #e53e3e;
            padding: 5px 12px;
            border-radius: 20px;
            font-weight: 600;
            margin-top: 5px;
            border: 1px solid #fed7d7;
        }

        .standards {
            display: flex;
            flex-wrap: wrap;
            gap: 8px;
            margin-top: 10px;
        }

        .standard-tag {
            background: #ebf8ff;
            color: #3182ce;
            padding: 4px 10px;
            border-radius: 4px;
            font-size: 0.85rem;
            font-weight: 500;
        }

        .special-req {
            background: #f0fff4;
            padding: 15px;
            border-radius: 8px;
            margin-top: 15px;
            border-left: 3px solid #38a169;
            color: #333;
        }

        /* 优化后的温度可视化控制条 */
        .temperature-visualization {
            background: white;
            border-radius: 12px;
            padding: 30px;
            margin-top: 40px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            border: 1px solid #e0e7ff;
        }

        .temperature-header {
            text-align: center;
            margin-bottom: 35px;
        }

        .temperature-header h2 {
            color: #0056b3;
            font-size: 1.8rem;
            margin-bottom: 10px;
        }
        .temperature-header p {
            color: #4a5568;
            max-width: 700px;
            margin: 0 auto;
        }

        /* 重新设计的温度标记线容器 */
        .temperature-markers-container {
            position: relative;
            height: 120px;
            margin: 40px 0 60px;
        }

        .temperature-line {
            position: absolute;
            top: 50%;
            left: 0;
            width: 100%;
            height: 8px; /* 加粗温度线 */
            background: linear-gradient(90deg, 
                #1e40af, #3b82f6, #60a5fa, #10b981, #f59e0b, #ef4444, #8b5cf6);
            border-radius: 8px;
            transform: translateY(-50%);
            box-shadow: 0 3px 10px rgba(0,0,0,0.1);
        }

        .temperature-markers {
            position: absolute;
            top: 50%;
            left: 0;
            width: 100%;
            display: flex;
            justify-content: space-between;
            transform: translateY(-50%);
        }

        .marker {
            position: relative;
            width: 2px;
            height: 25px;
            background: #4a5568;
        }

        .marker-label {
            position: absolute;
            top: -35px;
            left: 50%;
            transform: translateX(-50%);
            font-size: 0.85rem;
            font-weight: 500;
            color: #4a5568;
            white-space: nowrap;
            padding: 4px 10px;
            border-radius: 4px;
            background: rgba(255, 255, 255, 0.95);
            box-shadow: 0 2px 8px rgba(0,0,0,0.12);
            border: 1px solid #e2e8f0;
        }

        .temperature-range-labels {
            position: absolute;
            top: 50%;
            left: 0;
            width: 100%;
            transform: translateY(25px);
        }

        .range-label-box {
            position: absolute;
            text-align: center;
            transform: translateX(-50%);
            min-width: 120px;
            transition: all 0.3s ease;
        }

        .range-label-box:hover {
            transform: translateX(-50%) scale(1.05);
        }

        .range-label {
            font-size: 0.9rem;
            font-weight: 600;
            color: #2d3748;
            background: rgba(255,255,255,0.95);
            padding: 8px 15px;
            border-radius: 8px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.12);
            white-space: nowrap;
            transition: all 0.3s ease;
        }

        .range-value {
            font-size: 1rem;
            font-weight: 700;
            color: #e53e3e;
            margin-top: 5px;
            background: #fff5f5;
            padding: 4px 10px;
            border-radius: 20px;
            display: inline-block;
        }

        .temperature-ranges {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 20px;
            margin-top: 50px;
        }

        .temp-range-item {
            display: flex;
            align-items: center;
            background: #f8fafc;
            padding: 12px 20px;
            border-radius: 8px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            min-width: 260px;
            cursor: pointer;
            transition: all 0.3s ease;
            border: 2px solid transparent;
        }

        .temp-range-item:hover {
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            border-color: #cbd5e0;
        }

        .temp-range-item.active-range {
            transform: scale(1.05);
            box-shadow: 0 0 0 3px #3b82f6, 0 8px 25px rgba(59, 130, 246, 0.25);
            border-color: #3b82f6;
            background: #eff6ff;
        }

        .color-indicator {
            width: 25px;
            height: 25px;
            border-radius: 5px;
            margin-right: 15px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }

        .temp-range-info {
            line-height: 1.4;
        }

        .temp-range-name {
            font-weight: 600;
            color: #2d3748;
            font-size: 1.1rem;
        }

        .temp-range-value {
            font-weight: 700;
            color: #f7960f;
            font-size: 1.1rem;
        }

        .mobile-temp-info {
            display: none;
            text-align: center;
            padding: 15px;
            background: #f8fafc;
            border-radius: 8px;
            margin-top: 20px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }

        @keyframes pulse {
            0% { transform: scale(1); }
            50% { transform: scale(1.05); }
            100% { transform: scale(1); }
        }

        @media (max-width: 992px) {
            .temperature-ranges {
                gap: 15px;
            }
            
            .temp-range-item {
                min-width: calc(50% - 15px);
            }
            
            .range-label-box {
                min-width: 100px;
            }
        }

        @media (max-width: 768px) {
            .cs-grid {
                grid-template-columns: 1fr;
            }
            
            .cs-header h1 {
                font-size: 2rem;
            }
            
            .cs-tabs {
                flex-direction: column;
                gap: 10px;
            }
            
            .cs-tab {
                width: 100%;
            }
            
            .temperature-markers-container {
                height: 150px;
                margin: 30px 0 40px;
            }
            
            .temperature-line {
                height: 6px;
            }
            
            .marker {
                height: 20px;
            }
            
            .marker-label {
                font-size: 0.75rem;
                top: -30px;
                padding: 3px 8px;
            }
            
            .temperature-ranges {
                gap: 12px;
            }
            
            .temp-range-item {
                min-width: 100%;
            }
            
            .range-label {
                font-size: 0.8rem;
                padding: 6px 12px;
            }
            
            .range-value {
                font-size: 0.9rem;
            }
            
            /* 在移动端隐藏温度范围标签 */
            .temperature-range-labels {
                display: none;
            }
            
            /* 在移动端显示替代信息 */
            .mobile-temp-info {
                display: block;
                animation: fadeIn 0.5s ease;
            }
            
            .temp-range-name {
                font-size: 1rem;
            }
            
            .temp-range-value {
                font-size: 1rem;
            }
        }

        @media (max-width: 480px) {
            .cs-container {
                padding: 15px;
            }
            
            .cs-header h1 {
                font-size: 1.7rem;
            }
            
            .cs-header p {
                font-size: 1rem;
            }
            
            .card-header h3 {
                font-size: 1.2rem;
            }
            
            .temperature-visualization {
                padding: 20px 15px;
            }
            
            .temperature-header h2 {
                font-size: 1.5rem;
            }
            
            .range-label-box {
                min-width: 80px;
            }
            
            .range-label {
                font-size: 0.75rem;
                padding: 5px 10px;
            }
            
            .range-value {
                font-size: 0.85rem;
            }
            
            .temp-range-name {
                font-size: 1rem;
            }
            
            .temp-range-value {
                font-size: 1rem;
            }
            
            .marker-label {
                font-size: 0.7rem;
                top: -28px;
            }
        }
    /* --- Features grid layout --- */
    .features-grid {
        display: grid;
        /* Responsive grid with 4 columns on large screens, 2 on medium, and 1 on small */
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 1px;
        background-color: rgba(255, 255, 255, 0.6);
        padding: 0;
        color: #4b5563;
    }

    /* --- Feature card --- */
    .feature-card {
        background-color: transparent;
        padding: 2.5rem 1.5rem;
        text-align: center;
        transition: background-color 0.3s ease, transform 0.3s ease;
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
        border: 1px solid #e0e7ff;
    }

    .feature-card:hover {
        background-color: rgba(255, 255, 255, 0.5);
        transform: translateY(-5px);
        box-shadow: 0 10px 20px var(--shadow-light);
    }

    .feature-icon {
        width: 50px;
        height: 50px;
        margin: 0 auto 1.25rem;
        color: var(--primary-accent);
    }

    .feature-card h3 {
        font-size: 1.2rem;
        font-weight: 600;
        margin: 0 0 0.5rem 0;
        color: var(--text-dark);
    }

    .feature-card p {
        font-size: 0.95rem;
        color: var(--text-medium);
        margin: 0;
        line-height: 1.5;
    }
    
    /* --- Responsive design --- */
    @media (max-width: 768px) {
        body {
            padding: 2rem 1rem;
        }
        .header h1 {
            font-size: 2rem;
        }
        .header p {
            font-size: 1rem;
        }
    }
    
    @media (max-width: 576px) {
        .header h1 {
            font-size: 1.8rem;
        }
    }