/* roulang page: index */
:root {
      --deep-space: #0B0F1A;
      --space-gradient: #141B2D;
      --star-gold: #C9A96E;
      --star-gold-hover: #B8944F;
      --nebula-blue: #4B6E8C;
      --warm-white: #FAF9F7;
      --card-bg: #FFFFFF;
      --border-light: #E8E6E1;
      --text-dark: #1F2937;
      --text-secondary: #6B7280;
      --text-light: #F9FAFB;
      --shadow-sm: 0 2px 12px rgba(11,15,26,0.06);
      --shadow-md: 0 8px 24px rgba(11,15,26,0.12);
      --radius-sm: 6px;
      --radius-md: 8px;
      --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
      --font-serif: "Noto Serif SC", "STSong", serif;
      --transition: all 0.25s ease;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body { font-family: var(--font-sans); background-color: var(--warm-white); color: var(--text-dark); line-height: 1.75; font-size: 16px; }
    h1, h2, h3 { font-family: var(--font-serif); }
    a { text-decoration: none; color: inherit; }
    img { max-width: 100%; height: auto; display: block; }
    .container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
    .section-padding { padding: 80px 0; }
    .gold-text { color: var(--star-gold); }
    .text-secondary { color: var(--text-secondary); }
    .bg-deep { background-color: var(--deep-space); }
    .bg-warm { background-color: var(--warm-white); }
    .btn { display: inline-block; font-weight: 600; border-radius: var(--radius-sm); transition: var(--transition); cursor: pointer; text-align: center; font-family: var(--font-sans); }
    .btn-primary { background: var(--star-gold); color: var(--deep-space); padding: 12px 28px; border: none; }
    .btn-primary:hover { background: var(--star-gold-hover); box-shadow: inset 0 2px 6px rgba(0,0,0,0.15); }
    .btn-secondary { background: transparent; border: 2px solid var(--nebula-blue); color: var(--nebula-blue); padding: 12px 28px; }
    .btn-secondary:hover { background: var(--nebula-blue); color: white; }
    .card { background: var(--card-bg); border: 1px solid var(--border-light); border-radius: var(--radius-md); padding: 24px; box-shadow: var(--shadow-sm); transition: var(--transition); }
    .card:hover { box-shadow: var(--shadow-md); transform: translateY(-4px); }

/* Header / Nav */
    .site-header { position: fixed; top: 0; left: 0; width: 100%; background: #FFFFFF; box-shadow: 0 1px 4px rgba(0,0,0,0.04); z-index: 100; height: 64px; display: flex; align-items: center; }
    .header-inner { display: flex; align-items: center; justify-content: space-between; width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; height: 100%; }
    .logo-area { display: flex; align-items: center; gap: 8px; }
    .logo-star { width: 24px; height: 24px; background: var(--star-gold); border-radius: 50%; display: inline-block; }
    .logo-text { font-family: var(--font-serif); font-weight: 700; font-size: 20px; color: var(--deep-space); }
    .desktop-nav { display: flex; align-items: center; gap: 32px; }
    .desktop-nav a { font-size: 15px; color: #4B5563; padding: 8px 0; border-bottom: 2px solid transparent; transition: var(--transition); }
    .desktop-nav a:hover, .desktop-nav a.active { color: var(--star-gold); border-bottom-color: var(--star-gold); }
    .header-right { display: flex; align-items: center; gap: 16px; }
    .search-box { display: flex; align-items: center; background: #F9FAFB; border: 1px solid var(--border-light); border-radius: 20px; padding: 6px 16px; }
    .search-box i { color: var(--text-secondary); font-size: 14px; }
    .search-box input { border: none; background: transparent; outline: none; margin-left: 8px; font-size: 14px; width: 140px; }
    .hamburger { display: none; font-size: 24px; color: var(--deep-space); cursor: pointer; }
    @media (max-width: 1024px) {
      .desktop-nav, .header-right .search-box, .header-right .btn { display: none; }
      .hamburger { display: block; }
      .mobile-menu { display: none; position: absolute; top: 64px; left: 0; width: 100%; background: white; flex-direction: column; padding: 16px 24px; box-shadow: 0 8px 20px rgba(0,0,0,0.1); }
      .mobile-menu.open { display: flex; }
      .mobile-menu a { padding: 12px 0; border-bottom: 1px solid var(--border-light); color: var(--text-dark); }
      .mobile-menu .search-mobile { margin: 8px 0; display: flex; background: #F9FAFB; border-radius: 20px; padding: 8px 16px; border: 1px solid var(--border-light); }
    }

/* Hero */
    #hero { padding-top: 120px; padding-bottom: 80px; background: linear-gradient(90deg, #FAF9F7 55%, #F2F0EB 45%); }
    .hero-grid { display: flex; align-items: center; gap: 40px; }
    .hero-left { flex: 0 0 55%; }
    .hero-left h1 { font-size: 48px; line-height: 1.2; letter-spacing: 0.02em; margin-bottom: 16px; }
    .hero-left h1 .gold { font-size: 52px; } 
    .hero-sub { font-size: 18px; color: var(--text-secondary); max-width: 480px; margin: 20px 0 30px; }
    .hero-stats { display: flex; gap: 40px; margin: 32px 0; }
    .stat-item .stat-num { font-size: 28px; font-weight: 700; color: var(--star-gold); }
    .hero-right { flex: 0 0 45%; position: relative; display: flex; justify-content: center; align-items: center; }
    .orbit-container { width: 480px; height: 480px; background: #F0EEE8; border-radius: 50%; position: relative; display: flex; align-items: center; justify-content: center; }
    .orbit-ring { position: absolute; border: 2px solid rgba(201,169,110,0.25); border-radius: 50%; }
    .ring1 { width: 380px; height: 380px; animation: spin 20s linear infinite; }
    .ring2 { width: 300px; height: 300px; animation: spin 15s linear infinite reverse; }
    .ring3 { width: 220px; height: 220px; animation: spin 25s linear infinite; }
    .orbit-dot { width: 10px; height: 10px; background: var(--star-gold); border-radius: 50%; position: absolute; top: -5px; left: 50%; margin-left: -5px; }
    .center-logo { font-size: 80px; font-weight: 700; color: var(--deep-space); z-index: 5; }
    @keyframes spin { 100% { transform: rotate(360deg); } }
    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; }
      .hero-left { text-align: center; }
      .hero-stats { justify-content: center; }
      .orbit-container { width: 320px; height: 320px; }
    }

.section-title { text-align: center; margin-bottom: 48px; }
    .section-title h2 { font-size: 32px; font-weight: 600; }
    .gold-underline { width: 40px; height: 4px; background: var(--star-gold); margin: 12px auto 0; }
    /* Features grid */
    .features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
    .feature-card { padding: 32px 24px; text-align: left; }
    .feature-icon { width: 48px; height: 48px; background: rgba(201,169,110,0.15); border-radius: 50%; display: flex; align-items: center; justify-content: center; margin-bottom: 20px; }
    .feature-icon i { color: var(--star-gold); font-size: 24px; }
    .arrow-link { display: flex; align-items: center; margin-top: 16px; color: var(--star-gold); font-weight: 500; }
    .arrow-link i { margin-left: 8px; transition: var(--transition); }
    .feature-card:hover .arrow-link i { transform: translateX(6px); }
    @media (max-width: 1024px) { .features-grid { grid-template-columns: repeat(2, 1fr); } }
    @media (max-width: 640px) { .features-grid { grid-template-columns: 1fr; } }
    /* Cases waterfall */
    .cases-masonry { column-count: 2; column-gap: 24px; }
    .case-card { break-inside: avoid; margin-bottom: 24px; transition: var(--transition); }
    .case-img { height: 220px; background: #E8E6E1; position: relative; overflow: hidden; border-radius: var(--radius-md) var(--radius-md) 0 0; }
    .case-img img { width: 100%; height: 100%; object-fit: cover; }
    .case-overlay { position: absolute; inset: 0; background: rgba(11,15,26,0.85); color: white; display: flex; align-items: center; justify-content: center; opacity: 0; transition: var(--transition); font-weight: bold; }
    .case-card:hover .case-overlay { opacity: 1; }
    .case-info { padding: 16px; }
    .tag { background: #F5F3EE; color: var(--star-gold); font-size: 12px; padding: 2px 10px; border-radius: 4px; }
    @media (max-width: 768px) { .cases-masonry { column-count: 1; } }
    /* Solutions */
    .solution-cards { display: flex; gap: 30px; align-items: stretch; }
    .solution-left, .solution-right { flex: 1; padding: 40px; border-radius: var(--radius-md); }
    .solution-left { background: #F9F8F5; }
    .solution-right { background: var(--deep-space); color: white; }
    .solution-right h3, .solution-right p, .solution-right li { color: white; }
    .divider-dash { width: 1px; border-left: 2px dashed var(--border-light); margin: 0 10px; }
    @media (max-width: 768px) { .solution-cards { flex-direction: column; } .divider-dash { display: none; } }
    /* FAQ */
    .faq-list { max-width: 800px; margin: 0 auto; }
    .faq-item { border-bottom: 1px solid var(--border-light); padding: 16px 0; cursor: pointer; position: relative; }
    .faq-question { display: flex; justify-content: space-between; align-items: center; }
    .faq-num { font-size: 48px; color: #E8E6E1; margin-right: 20px; }
    .faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; color: var(--text-secondary); }
    .faq-item.open .faq-answer { max-height: 200px; margin-top: 12px; }
    /* CTA Banner */
    .cta-banner { background: var(--deep-space); padding: 80px 0; text-align: center; color: white; }
    .contact-row { display: flex; gap: 40px; margin-top: 40px; }
    .contact-form { flex: 2; }
    .contact-info { flex: 1; }
    .contact-form input, .contact-form textarea { width: 100%; padding: 14px; margin-bottom: 16px; border: 1px solid var(--nebula-blue); border-radius: 4px; background: white; }
    .social-icons i { font-size: 24px; margin-right: 16px; color: var(--nebula-blue); transition: var(--transition); }
    .social-icons i:hover { color: var(--star-gold); }
    .footer-bottom { border-top: 1px solid var(--star-gold); padding: 20px 0; display: flex; justify-content: space-between; color: var(--text-secondary); }
    @media (max-width: 768px) { .contact-row { flex-direction: column; } .footer-bottom { flex-direction: column; gap: 10px; text-align: center; } }