:root {
            --primary: #c62828;
            --secondary: #37474f;
            --accent: #ff8f00;
            --light: #f5f5f5;
            --dark: #212121;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: var(--dark);
            line-height: 1.8;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            margin-bottom: 1rem;
            color: var(--secondary);
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: var(--transition);
        }
        .btn-primary {
            background-color: var(--primary);
            border-color: var(--primary);
            padding: 0.75rem 2rem;
            font-weight: 600;
            border-radius: 4px;
        }
        .btn-primary:hover {
            background-color: #b71c1c;
            border-color: #b71c1c;
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(198, 40, 40, 0.3);
        }
        .section-padding {
            padding: 5rem 0;
        }
        .section-title {
            position: relative;
            padding-bottom: 1rem;
            margin-bottom: 3rem;
            text-align: center;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--accent);
        }
        .bg-light-alt {
            background-color: #f9f9f9;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.98);
            box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
            padding: 1rem 0;
            transition: var(--transition);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary) !important;
        }
        .navbar-brand span {
            color: var(--secondary);
        }
        .nav-link {
            font-weight: 600;
            margin: 0 0.5rem;
            color: var(--secondary) !important;
            position: relative;
        }
        .nav-link:hover, .nav-link.active {
            color: var(--primary) !important;
        }
        .nav-link::after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            background: var(--primary);
            left: 50%;
            bottom: 0;
            transition: var(--transition);
        }
        .nav-link:hover::after, .nav-link.active::after {
            width: 80%;
            left: 10%;
        }
        .hero {
            background: linear-gradient(rgba(33, 33, 33, 0.85), rgba(55, 71, 79, 0.9)), url('https://images.unsplash.com/photo-1497366754035-f200968a6e72?ixlib=rb-4.0.3&auto=format&fit=crop&w=1600&q=80') center/cover no-repeat;
            color: white;
            padding: 10rem 0 6rem;
            margin-top: 76px;
        }
        .hero h1 {
            color: white;
            font-size: 3.5rem;
            margin-bottom: 1.5rem;
            text-shadow: 0 2px 10px rgba(0,0,0,0.3);
        }
        .hero p {
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto 2rem;
        }
        .service-card, .project-card, .news-card {
            background: white;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
            transition: var(--transition);
            height: 100%;
        }
        .service-card:hover, .project-card:hover, .news-card:hover {
            transform: translateY(-15px);
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
        }
        .card-img-top {
            height: 220px;
            object-fit: cover;
            transition: var(--transition);
        }
        .service-card:hover .card-img-top {
            transform: scale(1.05);
        }
        .card-body {
            padding: 1.75rem;
        }
        .card-title {
            color: var(--primary);
            font-weight: 700;
        }
        .icon-box {
            width: 70px;
            height: 70px;
            background: var(--primary);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: -35px auto 1.5rem;
            font-size: 1.8rem;
            box-shadow: 0 5px 15px rgba(198, 40, 40, 0.3);
        }
        .counter-box {
            text-align: center;
            padding: 2rem;
            background: white;
            border-radius: 10px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
        }
        .counter {
            font-size: 3.5rem;
            font-weight: 800;
            color: var(--primary);
            display: block;
            line-height: 1;
        }
        .timeline {
            position: relative;
            padding-left: 30px;
        }
        .timeline::before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            bottom: 0;
            width: 3px;
            background: var(--accent);
        }
        .timeline-item {
            position: relative;
            margin-bottom: 2.5rem;
        }
        .timeline-item::before {
            content: '';
            position: absolute;
            left: -36px;
            top: 5px;
            width: 15px;
            height: 15px;
            border-radius: 50%;
            background: var(--primary);
            border: 3px solid white;
            box-shadow: 0 0 0 3px var(--accent);
        }
        .partner-logo {
            display: flex;
            align-items: center;
            justify-content: center;
            height: 100px;
            padding: 1.5rem;
            background: white;
            border-radius: 8px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            transition: var(--transition);
            filter: grayscale(100%);
            opacity: 0.7;
        }
        .partner-logo:hover {
            filter: grayscale(0);
            opacity: 1;
            transform: translateY(-5px);
        }
        .partner-logo img {
            max-height: 60px;
            max-width: 80%;
            object-fit: contain;
        }
        .contact-info-box {
            background: white;
            padding: 2rem;
            border-radius: 10px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
            text-align: center;
            height: 100%;
            transition: var(--transition);
        }
        .contact-info-box:hover {
            transform: translateY(-10px);
        }
        .contact-icon {
            width: 70px;
            height: 70px;
            background: var(--primary);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            font-size: 1.8rem;
        }
        .footer {
            background-color: var(--secondary);
            color: rgba(255, 255, 255, 0.85);
            padding: 4rem 0 2rem;
        }
        .footer h5 {
            color: white;
            margin-bottom: 1.5rem;
            position: relative;
            padding-bottom: 0.75rem;
        }
        .footer h5::after {
            content: '';
            position: absolute;
            left: 0;
            bottom: 0;
            width: 40px;
            height: 2px;
            background-color: var(--accent);
        }
        .footer a {
            color: rgba(255, 255, 255, 0.75);
            display: block;
            margin-bottom: 0.75rem;
            transition: var(--transition);
        }
        .footer a:hover {
            color: white;
            padding-left: 8px;
        }
        .social-links a {
            display: inline-block;
            width: 40px;
            height: 40px;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 50%;
            text-align: center;
            line-height: 40px;
            margin-right: 10px;
            transition: var(--transition);
        }
        .social-links a:hover {
            background: var(--primary);
            transform: translateY(-5px);
        }
        .copyright {
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            padding-top: 2rem;
            margin-top: 3rem;
            text-align: center;
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.6);
        }
        .friendlink {
            background-color: white;
            padding: 3rem 0;
        }
        .flink {
            display: inline-block;
            padding: 0.6rem 1.5rem;
            margin: 0.5rem;
            background: #f5f7fa;
            border-radius: 30px;
            color: var(--secondary);
            font-weight: 500;
            transition: var(--transition);
            border: 1px solid #eaeaea;
        }
        .flink:hover {
            background: var(--primary);
            color: white;
            border-color: var(--primary);
            transform: translateY(-3px);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background: var(--primary);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            box-shadow: 0 5px 15px rgba(198, 40, 40, 0.4);
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        @media (max-width: 992px) {
            .hero h1 {
                font-size: 2.8rem;
            }
            .section-padding {
                padding: 3rem 0;
            }
        }
        @media (max-width: 768px) {
            .hero h1 {
                font-size: 2.2rem;
            }
            .hero {
                padding: 8rem 0 4rem;
            }
            .counter {
                font-size: 2.8rem;
            }
            .navbar-nav {
                text-align: center;
                padding: 1rem 0;
            }
        }