/* roulang page: index */
:root {
            --primary-deep-blue: #1A2B4C;
            --primary-deep-blue-darker: #0F1D33;
            --accent-warm-gold: #C49A6C;
            --accent-warm-gold-hover: #B0854F;
            --bg-warm-white: #F7F5F2;
            --text-heading: #0F1D33;
            --text-body: #4A5568;
            --text-muted: #718096;
            --white: #FFFFFF;
            --border-light: rgba(26,43,76,0.06);
            --border-medium: rgba(26,43,76,0.12);
            --shadow-sm: 0 4px 20px rgba(26,43,76,0.06);
            --shadow-md: 0 8px 30px rgba(26,43,76,0.10);
            --shadow-lg: 0 12px 40px rgba(26,43,76,0.12);
            --shadow-hero: 0 20px 60px rgba(26,43,76,0.20);
            --radius-sm: 8px;
            --radius-md: 12px;
            --radius-card: 14px;
            --transition: 0.3s ease;
            --transition-fast: 0.2s ease;
            --max-width: 1280px;
        }

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

        html {
            scroll-behavior: smooth;
            font-size: 16px;
        }

        body {
            font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
            background-color: var(--bg-warm-white);
            color: var(--text-body);
            line-height: 1.7;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            font-weight: 400;
        }

        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 32px;
        }

        @media (max-width: 1023px) {
            .container { padding: 0 24px; }
        }
        @media (max-width: 767px) {
            .container { padding: 0 20px; }
            html { font-size: 15px; }
            body { font-size: 15px; }
            h1 { font-size: 34px !important; }
            h2 { font-size: 28px !important; }
        }

        h1, h2, h3, h4, .stat-number, .nav-link, .cta-text {
            color: var(--text-heading);
            font-weight: 700;
        }
        img { max-width: 100%; display: block; height: auto; }
        a { text-decoration: none; color: inherit; transition: var(--transition-fast); }
        button, input, select, textarea { font: inherit; }

        .gold-accent { color: var(--accent-warm-gold); }
        .text-gold { color: var(--accent-warm-gold); }

        /************ 导航 header ***********/
        #header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            background: rgba(255,255,255,0.92);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border-bottom: 1px solid var(--border-light);
            transition: var(--transition);
            padding: 14px 0;
        }
        #header.shadow {
            box-shadow: 0 4px 18px rgba(26,43,76,0.07);
        }
        .nav-container {
            max-width: var(--max-width);
            margin: 0 auto;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 32px;
        }
        .logo {
            font-size: 27px;
            font-weight: 700;
            letter-spacing: 0.5px;
            color: var(--primary-deep-blue);
            display: flex;
            align-items: center;
            cursor: pointer;
        }
        .logo .diamond {
            display: inline-block;
            width: 14px;
            height: 14px;
            background: var(--accent-warm-gold);
            transform: rotate(45deg);
            margin-right: 8px;
            border-radius: 2px;
        }
        .logo span { color: var(--primary-deep-blue); }

        .nav-links {
            display: flex;
            align-items: center;
            gap: 32px;
            font-size: 15px;
            color: var(--text-body);
            font-weight: 500;
            white-space: nowrap;
        }
        .nav-link {
            position: relative;
            cursor: pointer;
            transition: var(--transition-fast);
            line-height: 1.2;
        }
        .nav-link:hover, .nav-link:focus-visible {
            color: var(--accent-warm-gold);
            outline: none;
        }
        .nav-cta {
            background: var(--accent-warm-gold);
            color: white !important;
            padding: 10px 26px;
            border-radius: 8px;
            font-weight: 600;
            box-shadow: var(--shadow-sm);
            transition: var(--transition);
            cursor: pointer;
            display: inline-block;
        }
        .nav-cta:hover { background: var(--accent-warm-gold-hover); color: white; box-shadow: var(--shadow-md); }

        .menu-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 26px;
            cursor: pointer;
            color: var(--primary-deep-blue);
        }

        @media (max-width: 1023px) {
            .nav-links { display: none; }
            .menu-toggle { display: inline-block; }
            .nav-container { padding: 0 20px; }
            #mobile-nav.expanded {
                display: flex;
                flex-direction: column;
                background: var(--primary-deep-blue);
                color: white;
                position: absolute;
                top: 100%;
                left: 0;
                width: 100%;
                padding: 28px 20px;
                gap: 18px;
                box-shadow: 0 1px 0 var(--border-medium);
            }
            .nav-link.mobile { display: block; color: white; font-size: 18px; font-weight: 500; }
            .nav-link.mobile:hover { color: var(--accent-warm-gold); }
            .nav-mobile-cta { border: 1px solid white; color: white !important; background: transparent; padding: 10px 20px; text-align: center; border-radius: 12px; opacity: 0.9; }
        }