/* roulang page: index */
/* ===== CSS DESIGN SYSTEM ===== */
    :root {
      --primary: #5B2C8E;
      --primary-light: #7B4DB5;
      --accent: #D4AF37;
      --accent-light: #F8E7A1;
      --dark-bg: #1E1E2C;
      --dark-surface: #252536;
      --light-bg: #F8F7FC;
      --card-bg: #FFFFFF;
      --text-primary: #1E1E2C;
      --text-secondary: #5A5A72;
      --text-on-dark: #FFFFFF;
      --text-on-dark-muted: #B0B0C0;
      --border-light: #E8E7F0;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 20px rgba(0,0,0,0.06);
      --shadow-lg: 0 12px 28px rgba(0,0,0,0.08);
      --shadow-glow: 0 0 20px rgba(212,175,55,0.35);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-xl: 24px;
      --radius-pill: 50px;
      --space-xs: 8px;
      --space-sm: 16px;
      --space-md: 24px;
      --space-lg: 40px;
      --space-xl: 60px;
      --space-2xl: 80px;
      --transition: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      --font-stack: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
    }

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

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

    body {
      font-family: var(--font-stack);
      background-color: var(--light-bg);
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      overflow-x: hidden;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    button, .btn {
      cursor: pointer;
      font-family: var(--font-stack);
      border: none;
      outline: none;
      transition: all var(--transition);
    }

    input {
      font-family: var(--font-stack);
      outline: none;
    }

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 var(--space-md);
    }

    /* ===== TYPOGRAPHY ===== */
    h1 {
      font-size: 48px;
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: -0.5px;
    }
    h2 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: var(--space-md);
    }
    h3 {
      font-size: 24px;
      font-weight: 600;
      line-height: 1.4;
      margin-bottom: var(--space-xs);
    }
    h4 {
      font-size: 20px;
      font-weight: 600;
      line-height: 1.5;
    }
    p {
      font-size: 16px;
      font-weight: 400;
      line-height: 1.75;
      margin-bottom: 1.2em;
      color: var(--text-secondary);
    }
    .text-small {
      font-size: 14px;
      line-height: 1.6;
    }

    /* ===== BUTTONS ===== */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.3px;
      white-space: nowrap;
    }
    .btn-primary {
      background: var(--primary);
      color: var(--text-on-dark);
      box-shadow: 0 4px 12px rgba(91,44,142,0.3);
    }
    .btn-primary:hover {
      background: var(--primary-light);
      box-shadow: var(--shadow-glow);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: rgba(91,44,142,0.08);
      border-color: var(--primary-light);
    }
    .btn-accent {
      background: var(--accent);
      color: #1E1E2C;
      font-weight: 700;
      box-shadow: 0 4px 14px rgba(212,175,55,0.4);
    }
    .btn-accent:hover {
      background: #E0BF4A;
      box-shadow: var(--shadow-glow);
      transform: translateY(-2px);
    }
    .btn-lg {
      padding: 16px 40px;
      font-size: 18px;
    }

    /* ===== HEADER / NAVIGATION ===== */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background var(--transition), backdrop-filter var(--transition);
      background: transparent;
      backdrop-filter: blur(0px);
    }
    .site-header.scrolled {
      background: rgba(30, 30, 44, 0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.15);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      padding: 0 var(--space-md);
      max-width: 1200px;
      margin: 0 auto;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 22px;
      font-weight: 800;
      color: var(--accent);
      letter-spacing: 1px;
    }
    .logo svg {
      width: 32px;
      height: 32px;
      fill: var(--accent);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
    }
    .nav-links a {
      color: rgba(255,255,255,0.9);
      font-weight: 500;
      position: relative;
      padding: 6px 0;
      font-size: 15px;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
      border-radius: 2px;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent);
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .nav-cta {
      margin-left: 12px;
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 280px;
      height: 100vh;
      background: rgba(30,30,44,0.95);
      backdrop-filter: blur(20px);
      display: flex;
      flex-direction: column;
      padding: 32px 24px;
      gap: 28px;
      transition: right 0.4s ease;
      z-index: 1001;
      box-shadow: -10px 0 30px rgba(0,0,0,0.3);
    }
    .mobile-menu.open {
      right: 0;
    }
    .mobile-menu a {
      color: white;
      font-size: 18px;
      font-weight: 500;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    .mobile-menu .btn-primary {
      margin-top: 16px;
      text-align: center;
      width: 100%;
    }
    .mobile-overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.5);
      z-index: 1000;
      display: none;
    }
    .mobile-overlay.active {
      display: block;
    }

    /* ===== HERO SECTION ===== */
    .hero {
      background: radial-gradient(circle at 20% 20%, #3A1C5A, #1E1E2C);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding-top: 72px;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: var(--space-2xl);
      position: relative;
      z-index: 2;
    }
    .hero-content {
      flex: 1 1 60%;
      color: var(--text-on-dark);
    }
    .hero-content h1 {
      background: linear-gradient(135deg, #D4AF37 0%, #F8E7A1 70%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: var(--space-sm);
      font-size: 52px;
    }
    .hero-subtitle {
      font-size: 18px;
      color: #B0B0C0;
      margin-bottom: var(--space-lg);
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: var(--space-md);
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1 1 40%;
      position: relative;
      border-radius: var(--radius-xl);
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.4);
    }
    .hero-visual img {
      width: 100%;
      aspect-ratio: 4/3;
      object-fit: cover;
    }
    .hero-visual::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(91,44,142,0.35), rgba(30,30,44,0.5));
      pointer-events: none;
    }
    .particles {
      position: absolute;
      width: 100%;
      height: 100%;
      top: 0;
      left: 0;
      pointer-events: none;
      z-index: 1;
    }
    .particle {
      position: absolute;
      background: var(--accent);
      border-radius: 50%;
      opacity: 0.5;
      animation: float 6s infinite ease-in-out;
    }
    @keyframes float {
      0%, 100% { transform: translateY(0) scale(1); opacity: 0.4; }
      50% { transform: translateY(-20px) scale(1.2); opacity: 0.8; }
    }

    /* ===== SECTIONS ===== */
    section {
      padding: var(--space-2xl) 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: var(--space-xl);
    }
    .section-title h2 {
      color: var(--text-primary);
    }

    /* ===== FEATURES GRID ===== */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--space-md);
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      padding: var(--space-lg) var(--space-md);
      text-align: center;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      border: 1px solid transparent;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-lg);
      border-color: rgba(91,44,142,0.2);
    }
    .feature-icon {
      font-size: 40px;
      color: var(--accent);
      margin-bottom: var(--space-sm);
      transition: transform var(--transition);
    }
    .feature-card:hover .feature-icon {
      transform: scale(1.1);
    }
    .feature-card h3 {
      color: var(--text-primary);
    }

    /* ===== SCENARIOS ===== */
    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--space-lg);
    }
    .scenario-card {
      background: transparent;
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: transform var(--transition);
    }
    .scenario-card:hover {
      transform: translateY(-4px);
    }
    .scenario-card img {
      border-radius: var(--radius-md);
      aspect-ratio: 16/10;
      object-fit: cover;
      margin-bottom: var(--space-sm);
    }

    /* ===== CASES CAROUSEL ===== */
    .cases-wrapper {
      display: flex;
      gap: var(--space-md);
      overflow-x: auto;
      scroll-snap-type: x mandatory;
      -webkit-overflow-scrolling: touch;
      padding-bottom: var(--space-sm);
    }
    .case-card {
      flex: 0 0 calc(33.333% - 16px);
      min-width: 280px;
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      padding: var(--space-lg);
      box-shadow: var(--shadow-sm);
      scroll-snap-align: start;
      display: flex;
      flex-direction: column;
      gap: var(--space-sm);
    }
    .case-card blockquote {
      font-style: italic;
      font-size: 18px;
      color: var(--text-primary);
      position: relative;
      padding-left: 20px;
      border-left: 4px solid var(--accent);
    }
    .case-author {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .case-author img {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      object-fit: cover;
    }

    /* ===== FAQ ACCORDION ===== */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: var(--space-md) 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-size: 18px;
      font-weight: 600;
      color: var(--text-primary);
      transition: color var(--transition);
    }
    .faq-question:hover {
      color: var(--primary);
    }
    .faq-icon {
      font-size: 24px;
      transition: transform 0.3s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: var(--space-sm);
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* ===== CTA STRIP ===== */
    .cta-strip {
      background: var(--dark-bg);
      text-align: center;
      padding: var(--space-2xl) 0;
    }
    .cta-strip h2 {
      color: var(--text-on-dark);
    }
    .cta-form {
      display: flex;
      gap: 12px;
      justify-content: center;
      flex-wrap: wrap;
      margin-top: var(--space-md);
    }
    .cta-form input {
      padding: 14px 20px;
      border-radius: var(--radius-sm);
      border: 1px solid #ccc;
      background: white;
      min-width: 260px;
      transition: border var(--transition), box-shadow var(--transition);
    }
    .cta-form input:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(91,44,142,0.2);
    }

    /* ===== FOOTER ===== */
    .site-footer {
      background: var(--dark-bg);
      color: var(--text-on-dark-muted);
      padding: var(--space-2xl) 0 var(--space-md);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: var(--space-lg);
    }
    .footer-col h4 {
      color: white;
      margin-bottom: var(--space-sm);
    }
    .footer-col a {
      display: block;
      color: var(--text-on-dark-muted);
      margin-bottom: 8px;
    }
    .footer-col a:hover {
      color: var(--accent);
    }
    .social-icons {
      display: flex;
      gap: 12px;
      margin-top: 12px;
    }
    .social-icons span {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      border: 1px solid #555;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: all var(--transition);
    }
    .social-icons span:hover {
      background: var(--accent);
      border-color: var(--accent);
      color: #1E1E2C;
    }
    .copyright {
      text-align: center;
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: var(--space-xl);
      padding-top: var(--space-md);
      font-size: 14px;
    }

    /* ===== RESPONSIVE ===== */
    @media (max-width: 1024px) {
      h1 { font-size: 40px; }
      h2 { font-size: 30px; }
      .hero .container { flex-direction: column; }
      .hero-content, .hero-visual { flex: auto; width: 100%; }
      .features-grid { grid-template-columns: repeat(2, 1fr); }
      .scenarios-grid { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-toggle { display: block; }
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      .hero-buttons .btn { width: 100%; }
      .features-grid { grid-template-columns: 1fr; }
      .scenarios-grid { grid-template-columns: 1fr; }
      .case-card { flex: 0 0 85%; }
      .footer-grid { grid-template-columns: 1fr; }
    }