/* 核心业务板块 */
        .core-section {
            position: relative;
            padding: 100px 5%;
            background: white;
            z-index: 2;
        }
        
        .section-header {
            text-align: center;
            max-width: 1400px;
            margin: 0 auto 80px;
        }
        
        .section-title {
            font-size: 1.8rem;
            font-weight: 300;
            margin-bottom: 10px;
            font-family: 'Orbitron', sans-serif;
            color: #fff;
            position: relative;
            display: inline-block;
        }
        
        .section-subtitle {
            font-size: 1rem;
            color: #fff;
            margin-top: 5px;
            max-width: 800px;
            margin-left: auto;
            margin-right: auto;
        }
        
        .video-background {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: -1;
            overflow: hidden;
            background: linear-gradient(135deg, #1a3a6d, #2a5298);
            background-size: cover;
        }
        
        .video-overlay {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.6);
        }
        
        .business-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 40px;
            max-width: 1400px;
            margin: 0 auto;
        }
        
        .business-card {
            background: rgba(255, 255, 255, 0.98);
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
            position: relative;
            z-index: 2;
            display: flex;
            flex-direction: column;
            height: 100%;
        }
        
        .card-header {
            padding: 30px 30px 20px;
            text-align: center;
            background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
        }
        
        .card-icon {
            font-size: 3.5rem;
            color: #1a3a6d;
            margin-bottom: 20px;
        }
        
        .card-title {
            font-size: 1.4rem;
            font-weight: 500;
            color: #1e293b;
            margin-bottom: 15px;
            font-family: 'Orbitron', sans-serif;
        }
        
        .card-content {
            padding: 30px;
            flex-grow: 1;
            display: flex;
            flex-direction: column;
        }
        
        .card-features {
            list-style: none;
            margin-bottom: 30px;
            flex-grow: 1;
        }
        
        .card-features li {
            padding: 12px 0;
            display: flex;
            align-items: flex-start;
            border-bottom: 1px solid #f1f5f9;
            line-height:40px;
            font-size:1.0rem;
            gap:10px;
            color:#333;
        }
        
        .card-features li i{
            line-height:40px;
            margin: 0 0;
        }
        
        .card-features li:last-child {
            border-bottom: none;
        }
        
        .feature-icon {
            color: #1a3a6d;
            margin-right: 15px;
            font-size: 1.2rem;
            margin-top: 3px;
            flex-shrink: 0;
        }
        
        .card-cta {
            display: block;
            text-align: center;
            padding: 14px;
            background: #1a3a6d;
            color: white;
            text-decoration: none;
            border-radius: 8px;
            font-weight: 500;
            transition: all 0.3s;
            margin-top: auto;
        }
        
        .card-cta:hover {
            background: #1d4ed8;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(37, 99, 235, 0.3);
        }
        
        .card-cta i {
            margin-left: 8px;
            transition: transform 0.3s;
        }
        
        /* 响应式设计 - 详细断点 */
        /* 1200px 以上 - 大桌面 */
        @media (min-width: 1200px) {
            .business-grid {
                gap: 40px;
            }
            
            .card-title {
                font-size: 1.5rem;
            }
        }
        
        /* 992px - 1199px：中等桌面 */
        @media (max-width: 1199px) and (min-width: 992px) {
            .business-grid {
                gap: 30px;
            }
            
            .card-header {
                padding: 25px 25px 15px;
            }
            
            .card-title {
                font-size: 1.3rem;
            }
            
            .card-content {
                padding: 25px;
            }
        }
        
        /* 768px - 991px：平板横屏和小桌面 */
        @media (max-width: 991px) and (min-width: 768px) {
            .business-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 30px;
            }
            
            .section-header {
                margin-bottom: 60px;
            }
            
            .card-header {
                padding: 25px 20px 15px;
            }
            
            .card-icon {
                font-size: 3rem;
            }
            
            .card-title {
                font-size: 1.25rem;
            }
            
            .card-features li {
                font-size: 0.95rem;
            }
            
            .core-section {
                padding: 80px 5%;
            }
        }
        
        /* 576px - 767px：平板竖屏和大手机 */
        @media (max-width: 767px) and (min-width: 576px) {
            .business-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 25px;
                max-width: 600px;
            }
            
            .section-header {
                margin-bottom: 50px;
            }
            
            .section-title {
                font-size: 1.6rem;
            }
            
            .section-subtitle {
                font-size: 0.95rem;
            }
            
            .card-header {
                padding: 22px 18px 12px;
            }
            
            .card-icon {
                font-size: 2.8rem;
                margin-bottom: 15px;
            }
            
            .card-title {
                font-size: 1.2rem;
            }
            
            .card-content {
                padding: 22px;
            }
            
            .card-features li {
                font-size: 0.9rem;
                padding: 10px 0;
            }
            
            .core-section {
                padding: 70px 5%;
            }
        }
        
        /* 480px - 575px：中等手机 */
        @media (max-width: 575px) and (min-width: 480px) {
            .business-grid {
                grid-template-columns: 1fr;
                max-width: 500px;
                gap: 25px;
            }
            
            .section-header {
                margin-bottom: 45px;
            }
            
            .section-title {
                font-size: 1.5rem;
            }
            
            .section-subtitle {
                font-size: 0.9rem;
            }
            
            .card-header {
                padding: 25px 20px 15px;
            }
            
            .card-icon {
                font-size: 3rem;
            }
            
            .card-title {
                font-size: 1.3rem;
            }
            
            .core-section {
                padding: 60px 5%;
            }
        }
        
        /* 320px - 479px：小手机 */
        @media (max-width: 479px) and (min-width: 320px) {
            .business-grid {
                grid-template-columns: 1fr;
                max-width: 100%;
                gap: 20px;
            }
            
            .section-header {
                margin-bottom: 40px;
            }
            
            .section-title {
                font-size: 1.4rem;
                margin-bottom: 8px;
            }
            
            .section-subtitle {
                font-size: 0.85rem;
            }
            
            .card-header {
                padding: 20px 15px 12px;
            }
            
            .card-icon {
                font-size: 2.5rem;
                margin-bottom: 12px;
            }
            
            .card-title {
                font-size: 1.2rem;
                margin-bottom: 10px;
            }
            
            .card-content {
                padding: 20px 15px;
            }
            
            .card-features li {
                font-size: 0.85rem;
                padding: 10px 0;
                line-height: 1.5;
            }
            
            .feature-icon {
                font-size: 1rem;
            }
            
            .card-cta {
                padding: 12px;
                font-size: 0.9rem;
            }
            
            .core-section {
                padding: 50px 4%;
            }
        }
        
        /* 小于320px：超小屏幕设备 */
        @media (max-width: 319px) {
            .business-grid {
                grid-template-columns: 1fr;
                gap: 18px;
            }
            
            .section-header {
                margin-bottom: 35px;
            }
            
            .section-title {
                font-size: 1.3rem;
            }
            
            .section-subtitle {
                font-size: 0.8rem;
            }
            
            .card-header {
                padding: 18px 12px 10px;
            }
            
            .card-icon {
                font-size: 2.2rem;
                margin-bottom: 10px;
            }
            
            .card-title {
                font-size: 1.1rem;
                margin-bottom: 8px;
            }
            
            .card-content {
                padding: 18px 12px;
            }
            
            .card-features li {
                font-size: 0.8rem;
                padding: 8px 0;
                line-height: 1.4;
            }
            
            .card-cta {
                padding: 10px;
                font-size: 0.85rem;
            }
            
            .core-section {
                padding: 40px 3%;
            }
        }
        
        /* 触摸设备优化 */
        @media (hover: none) and (pointer: coarse) {
            .business-card {
                transform: translateY(0) scale(1);
                box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
            }
            
            .business-card:active {
                transform: translateY(-5px) scale(1.02);
                box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
            }
            
            .card-cta:active {
                transform: translateY(-1px);
                box-shadow: 0 3px 10px rgba(37, 99, 235, 0.3);
            }
        }
        
        /* 桌面设备悬停效果 */
        @media (hover: hover) and (pointer: fine) {
            .business-card:hover {
                transform: translateY(-15px) scale(1.03);
                box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
            }
            
            .business-card:hover .card-cta {
                background: #1d4ed8;
            }
        }
        
        /* 打印样式优化 */
        @media print {
            .core-section {
                padding: 50px 5%;
                background: white;
            }
            
            .video-background, .video-overlay {
                display: none;
            }
            
            .section-title, .section-subtitle {
                color: #333 !important;
            }
            
            .business-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 20px;
            }
            
            .business-card {
                box-shadow: none;
                border: 1px solid #ddd;
                page-break-inside: avoid;
            }
            
            .card-cta {
                display: none;
            }
        }