:root {
            --sjb5-primary: #FF6600;
            --sjb5-primary-hover: #E65C00;
            --sjb5-secondary: #2B3648;
            --sjb5-text: #1D1D1F;
            --sjb5-text-light: #6E6E73;
            --sjb5-bg-light: #FBFBFD;
            --sjb5-white: #FFFFFF;
            --sjb5-shadow: 0 10px 30px rgba(0,0,0,0.08);
            --sjb5-container-width: 1320px;
        }

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

        body {
            font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--sjb5-text);
            background-color: var(--sjb5-bg-light);
            line-height: 1.6;
            overflow-x: hidden;
        }

        /* Layout Helpers */
        .sjb5-container {
            max-width: var(--sjb5-container-width);
            margin: 0 auto;
            padding: 0 24px;
            width: 100%;
        }

        .sjb5-flex {
            display: flex;
            flex-wrap: wrap;
        }

        .sjb5-flex-item {
            min-width: 0;
        }

        /* Typography */
        h1, h2, h3 {
            word-break: keep-all;
            white-space: normal;
            line-height: 1.2;
        }

        p {
            word-break: break-word;
            overflow-wrap: break-word;
            line-height: 1.8;
        }

        /* Navigation */
        .sjb5-header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.8);
            backdrop-filter: blur(20px);
            border-bottom: 1px solid rgba(0,0,0,0.05);
            transition: all 0.3s ease;
        }

        .sjb5-nav {
            height: 72px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
        }

        .sjb5-logo {
            flex-shrink: 0;
        }

        .sjb5-logo img {
            height: 32px;
            display: block;
        }

        .sjb5-menu {
            display: flex;
            gap: 24px;
            list-style: none;
            flex-wrap: wrap;
        }

        .sjb5-menu-link {
            text-decoration: none;
            color: var(--sjb5-text);
            font-weight: 500;
            font-size: 15px;
            transition: color 0.3s;
        }

        .sjb5-menu-link:hover {
            color: var(--sjb5-primary);
        }

        /* Hero Section */
        .sjb5-hero {
            padding: 160px 0 80px;
            text-align: center;
            background: radial-gradient(circle at top right, #FFF5EE 0%, #FFFFFF 100%);
        }

        .sjb5-hero-title {
            font-size: clamp(2.5rem, 5vw + 1rem, 4.5rem);
            font-weight: 700;
            margin-bottom: 24px;
            letter-spacing: -0.02em;
        }

        .sjb5-hero-subtitle {
            font-size: clamp(1.1rem, 1.5vw + 0.5rem, 1.5rem);
            color: var(--sjb5-text-light);
            max-width: 800px;
            margin: 0 auto 48px;
        }

        .sjb5-hero-mockup {
            width: 100%;
            max-width: 1000px;
            margin: 0 auto;
            position: relative;
        }

        .sjb5-hero-mockup img {
            width: 100%;
            height: auto;
            border-radius: 20px;
            box-shadow: 0 30px 60px rgba(0,0,0,0.12);
            transition: transform 0.5s ease;
        }

        .sjb5-hero-mockup:hover img {
            transform: translateY(-10px);
        }

        /* Download Section */
        .sjb5-download-hub {
            padding: 96px 0;
            background: var(--sjb5-white);
        }

        .sjb5-platform-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 32px;
            margin-top: 48px;
        }

        .sjb5-download-card {
            background: var(--sjb5-bg-light);
            padding: 48px;
            border-radius: 24px;
            border: 1px solid #F0F0F0;
            transition: all 0.3s ease;
            display: flex;
            flex-direction: column;
            align-items: center;
            text-align: center;
        }

        .sjb5-download-card:hover {
            transform: translateY(-8px);
            box-shadow: var(--sjb5-shadow);
            border-color: var(--sjb5-primary);
        }

        .sjb5-download-btn {
            display: inline-block;
            background: var(--sjb5-primary);
            color: white;
            padding: 16px 48px;
            border-radius: 50px;
            text-decoration: none;
            font-weight: 600;
            font-size: 18px;
            margin: 24px 0;
            transition: all 0.3s;
        }

        .sjb5-download-btn:hover {
            background: var(--sjb5-primary-hover);
            box-shadow: 0 8px 20px rgba(255, 102, 0, 0.3);
        }

        .sjb5-safety-badge {
            max-width: 200px;
            margin-top: 16px;
        }

        /* Features Section */
        .sjb5-feature-section {
            padding: 96px 0;
        }

        .sjb5-feature-block {
            display: flex;
            align-items: center;
            gap: 64px;
            margin-bottom: 96px;
        }

        .sjb5-feature-block:nth-child(even) {
            flex-direction: row-reverse;
        }

        .sjb5-feature-content {
            flex: 1;
            min-width: 0;
        }

        .sjb5-feature-image {
            flex: 1.2;
            min-width: 0;
        }

        .sjb5-feature-image img {
            width: 100%;
            border-radius: 20px;
            box-shadow: var(--sjb5-shadow);
        }

        .sjb5-feature-tag {
            color: var(--sjb5-primary);
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 2px;
            margin-bottom: 16px;
            display: block;
        }

        .sjb5-feature-title {
            font-size: clamp(1.8rem, 3vw, 2.5rem);
            margin-bottom: 24px;
        }

        .sjb5-tool-list {
            list-style: none;
            margin-top: 32px;
        }

        .sjb5-tool-item {
            background: rgba(255, 102, 0, 0.05);
            padding: 20px;
            border-radius: 12px;
            margin-bottom: 16px;
            border-left: 4px solid var(--sjb5-primary);
        }

        .sjb5-tool-name {
            font-weight: 700;
            display: block;
            margin-bottom: 4px;
        }

        /* Skin Section */
        .sjb5-skin-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
            gap: 24px;
            margin-top: 40px;
        }

        .sjb5-skin-tag {
            background: #f0f0f0;
            padding: 12px 20px;
            border-radius: 12px;
            font-weight: 500;
            text-align: center;
        }

        /* News Section */
        .sjb5-news-section {
            padding: 80px 0;
            background: #fdfdfd;
        }

        .sjb5-news-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 24px;
        }

        .sjb5-news-card {
            padding: 24px;
            background: white;
            border-radius: 16px;
            border: 1px solid #eee;
        }

        /* Footer */
        .sjb5-footer {
            background: var(--sjb5-secondary);
            color: rgba(255,255,255,0.7);
            padding: 80px 0 40px;
        }

        .sjb5-footer-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 48px;
            margin-bottom: 64px;
        }

        .sjb5-footer-brand {
            font-size: 24px;
            font-weight: 700;
            color: white;
            margin-bottom: 24px;
        }

        .sjb5-footer-title {
            color: white;
            font-size: 16px;
            margin-bottom: 24px;
            font-weight: 600;
        }

        .sjb5-footer-links {
            list-style: none;
        }

        .sjb5-footer-links li {
            margin-bottom: 12px;
        }

        .sjb5-footer-links a {
            color: rgba(255,255,255,0.6);
            text-decoration: none;
            transition: color 0.3s;
        }

        .sjb5-footer-links a:hover {
            color: var(--sjb5-primary);
        }

        .sjb5-footer-bottom {
            border-top: 1px solid rgba(255,255,255,0.1);
            padding-top: 40px;
            text-align: center;
            font-size: 14px;
        }

        /* Responsive */
        @media (max-width: 768px) {
            .sjb5-menu {
                display: none;
            }
            .sjb5-feature-block, .sjb5-feature-block:nth-child(even) {
                flex-direction: column;
                gap: 32px;
            }
            .sjb5-hero {
                padding: 120px 0 60px;
            }
        }