:root {
            --sjb5-primary: #FF6600;
            --sjb5-primary-dark: #E65C00;
            --sjb5-secondary: #2B2D42;
            --sjb5-bg-light: #F8F9FA;
            --sjb5-text-main: #333333;
            --sjb5-text-muted: #666666;
            --sjb5-white: #FFFFFF;
            --sjb5-shadow: 0 10px 30px rgba(255, 102, 0, 0.08);
            --sjb5-radius: 16px;
        }

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

        body {
            font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
            background-color: var(--sjb5-bg-light);
            color: var(--sjb5-text-main);
            line-height: 1.8;
            overflow-x: hidden;
        }

        /* Layout Constraints */
        .sjb5-container {
            max-width: 1100px;
            margin: 0 auto;
            padding: 0 24px;
            width: 100%;
        }

        /* Typography */
        h1, h2, h3 {
            word-break: keep-all;
            white-space: normal;
            font-weight: 700;
            line-height: 1.3;
        }

        p {
            word-break: break-word;
            overflow-wrap: break-word;
            font-size: clamp(1rem, 0.5vw + 0.8rem, 1.125rem);
        }

        /* Navigation */
        .sjb5-navbar {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            height: 72px;
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: blur(10px);
            z-index: 1000;
            border-bottom: 1px solid rgba(0,0,0,0.05);
            display: flex;
            align-items: center;
        }

        .sjb5-nav-wrapper {
            display: flex;
            justify-content: space-between;
            align-items: center;
            width: 100%;
            flex-wrap: wrap;
        }

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

        .sjb5-logo img {
            height: 32px;
            width: auto;
        }

        .sjb5-nav-links {
            display: flex;
            flex-wrap: wrap;
            gap: 20px;
            list-style: none;
            min-width: 0;
        }

        .sjb5-nav-links a {
            text-decoration: none;
            color: var(--sjb5-text-main);
            font-size: 14px;
            font-weight: 500;
            transition: color 0.3s;
        }

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

        /* Hero Section */
        .sjb5-hero {
            padding: 160px 0 80px;
            background: radial-gradient(circle at top right, rgba(255,102,0,0.05), transparent);
            text-align: center;
        }

        .sjb5-hero-title {
            font-size: clamp(2rem, 5vw + 1rem, 4rem);
            background: linear-gradient(135deg, var(--sjb5-secondary) 0%, var(--sjb5-primary) 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 24px;
        }

        .sjb5-hero-subtitle {
            max-width: 700px;
            margin: 0 auto;
            color: var(--sjb5-text-muted);
        }

        /* Installation Steps - The Core Tutorial */
        .sjb5-tutorial-section {
            padding: 64px 0;
        }

        .sjb5-step-card {
            display: flex;
            flex-wrap: wrap;
            background: var(--sjb5-white);
            border-radius: var(--sjb5-radius);
            margin-bottom: 48px;
            overflow: hidden;
            box-shadow: var(--sjb5-shadow);
            transition: transform 0.3s ease;
        }

        .sjb5-step-card:hover {
            transform: translateY(-8px);
        }

        .sjb5-step-content {
            flex: 1;
            min-width: 300px;
            padding: 48px;
            display: flex;
            flex-direction: column;
            justify-content: center;
        }

        .sjb5-step-number {
            font-size: 48px;
            color: rgba(255, 102, 0, 0.1);
            font-weight: 900;
            margin-bottom: -20px;
        }

        .sjb5-step-title {
            font-size: 28px;
            margin-bottom: 16px;
            color: var(--sjb5-secondary);
        }

        .sjb5-step-desc {
            color: var(--sjb5-text-muted);
            margin-bottom: 24px;
        }

        .sjb5-step-visual {
            flex: 1;
            min-width: 300px;
            background: #F0F2F5;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 40px;
            position: relative;
        }

        /* Custom Decorative UI Element instead of icons */
        .sjb5-ui-mockup {
            width: 80%;
            height: 180px;
            background: var(--sjb5-white);
            border-radius: 12px;
            border: 4px solid #E1E4E8;
            position: relative;
            box-shadow: 0 20px 40px rgba(0,0,0,0.05);
        }

        .sjb5-ui-mockup::after {
            content: '';
            position: absolute;
            top: 20px;
            left: 20px;
            right: 20px;
            height: 12px;
            background: #F0F2F5;
            border-radius: 6px;
        }

        /* Productivity Extension Grid */
        .sjb5-feature-section {
            padding: 96px 0;
            background: var(--sjb5-secondary);
            color: var(--sjb5-white);
            border-radius: 40px;
            margin: 40px 24px;
        }

        .sjb5-feature-header {
            text-align: center;
            margin-bottom: 64px;
        }

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

        .sjb5-feature-card {
            background: rgba(255,255,255,0.05);
            padding: 32px;
            border-radius: var(--sjb5-radius);
            border: 1px solid rgba(255,255,255,0.1);
            transition: all 0.3s;
        }

        .sjb5-feature-card:hover {
            background: rgba(255,255,255,0.1);
            border-color: var(--sjb5-primary);
        }

        .sjb5-tool-item {
            margin-top: 24px;
            padding-top: 24px;
            border-top: 1px solid rgba(255,255,255,0.1);
        }

        .sjb5-tool-name {
            display: block;
            color: var(--sjb5-primary);
            font-weight: bold;
            margin-bottom: 8px;
        }

        /* FAQ Section */
        .sjb5-faq-section {
            padding: 96px 0;
        }

        .sjb5-faq-list {
            display: flex;
            flex-direction: column;
            gap: 16px;
        }

        .sjb5-faq-item {
            background: var(--sjb5-white);
            border-radius: 12px;
            padding: 24px;
            cursor: pointer;
            transition: all 0.3s;
        }

        .sjb5-faq-item:hover {
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
        }

        .sjb5-faq-question {
            font-weight: 700;
            color: var(--sjb5-secondary);
            display: flex;
            justify-content: space-between;
        }

        /* Button Style */
        .sjb5-btn {
            display: inline-block;
            padding: 12px 32px;
            border-radius: 50px;
            background: var(--sjb5-primary);
            color: var(--sjb5-white);
            text-decoration: none;
            font-weight: 600;
            transition: all 0.3s;
            border: none;
            cursor: pointer;
            text-align: center;
        }

        .sjb5-btn:hover {
            background: var(--sjb5-primary-dark);
            transform: scale(1.05);
            box-shadow: 0 8px 20px rgba(255, 102, 0, 0.3);
        }

        /* Footer */
        .sjb5-footer {
            background: #1A1B26;
            color: rgba(255,255,255,0.6);
            padding: 80px 0 40px;
            margin-top: 80px;
        }

        .sjb5-footer-content {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 48px;
        }

        .sjb5-footer-brand h2 {
            color: var(--sjb5-white);
            margin-bottom: 16px;
        }

        .sjb5-footer-links {
            display: flex;
            gap: 64px;
            flex-wrap: wrap;
        }

        .sjb5-footer-col h4 {
            color: var(--sjb5-white);
            margin-bottom: 24px;
        }

        .sjb5-footer-col ul {
            list-style: none;
        }

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

        .sjb5-footer-col a {
            color: inherit;
            text-decoration: none;
            transition: color 0.3s;
        }

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

        .sjb5-copyright {
            margin-top: 64px;
            padding-top: 40px;
            border-top: 1px solid rgba(255,255,255,0.05);
            text-align: center;
            font-size: 14px;
        }

        /* Responsive */
        @media (max-width: 768px) {
            .sjb5-nav-links {
                display: none; /* In real project, use a hamburger menu */
            }
            .sjb5-step-card {
                flex-direction: column;
            }
            .sjb5-step-visual {
                order: -1;
            }
            .sjb5-feature-section {
                margin: 24px 12px;
                border-radius: 24px;
            }
        }
    


        @keyframes spin {
            to { transform: translate(-50%, -50%) rotate(360deg); }
        }