/* roulang page: index */
:root {
      --color-primary: #0F172A;
      --color-accent: #00F0FF;
      --color-accent-secondary: #A855F7;
      --color-gold: #F59E0B;
      --color-bg: #F8FAFC;
      --color-bg-alt: #F1F5F9;
      --color-text: #1E293B;
      --color-text-soft: #64748B;
      --color-white: #FFFFFF;
      --radius-card: 16px;
      --shadow-card: 0 8px 28px rgba(0,0,0,0.04), 0 2px 8px rgba(0,0,0,0.02);
      --shadow-hover: 0 18px 40px rgba(0,0,0,0.08), 0 6px 16px rgba(0,0,0,0.04);
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
      --transition: 0.25s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--color-bg);
      color: var(--color-text);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 16px rgba(0,0,0,0.02);
      z-index: 50;
      transition: var(--transition);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }

    .logo {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--color-primary);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--color-accent);
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      font-weight: 500;
      color: var(--color-text);
      transition: color 0.2s;
      font-size: 0.95rem;
    }

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

    .btn-primary {
      background: var(--color-accent);
      color: #0F172A;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: 8px;
      transition: all 0.25s;
      box-shadow: 0 4px 12px rgba(0,240,255,0.25);
      font-size: 0.95rem;
      white-space: nowrap;
    }

    .btn-primary:hover {
      background: #33F5FF;
      box-shadow: 0 0 20px rgba(0,240,255,0.6);
      transform: translateY(-1px);
    }

    .btn-outline {
      border: 2px solid var(--color-accent);
      background: transparent;
      color: var(--color-accent);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: 8px;
      transition: all 0.25s;
    }

    .btn-outline:hover {
      background: rgba(0,240,255,0.08);
      box-shadow: 0 0 14px rgba(0,240,255,0.4);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2.5px;
      background: var(--color-primary);
      border-radius: 2px;
      transition: 0.2s;
    }

    .mobile-menu {
      display: none;
    }

    /* Hero */
    .hero {
      background: radial-gradient(circle at 30% 40%, #1A0A2E 0%, #0F172A 100%);
      min-height: 90vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      margin-top: 70px;
    }

    .hero-content {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      flex-wrap: wrap;
      position: relative;
      z-index: 2;
    }

    .hero-text {
      flex: 1 1 500px;
    }

    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      color: white;
      line-height: 1.3;
      margin-bottom: 20px;
    }
    .hero .highlight {
      color: var(--color-accent);
    }

    .hero-sub {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
      max-width: 500px;
    }

    .hero-actions {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
    }

    .hero-visual {
      flex: 1 1 400px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 28px;
      min-height: 360px;
      box-shadow: 0 0 50px rgba(0,240,255,0.3);
      position: relative;
    }

    .particle {
      position: absolute;
      width: 6px;
      height: 6px;
      background: var(--color-accent);
      border-radius: 50%;
      opacity: 0.6;
      animation: float 6s infinite alternate;
    }

    @keyframes float {
      0% { transform: translateY(0px); opacity: 0.3; }
      100% { transform: translateY(-30px); opacity: 0.8; }
    }

    /* 通用板块 */
    section {
      padding: 90px 0;
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--color-primary);
      text-align: center;
    }

    .section-sub {
      color: var(--color-text-soft);
      text-align: center;
      max-width: 680px;
      margin: 0 auto 48px;
      font-size: 1.1rem;
    }

    /* 优势区 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .advantage-card {
      background: white;
      padding: 32px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      text-align: center;
    }
    .advantage-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .adv-icon {
      font-size: 2.6rem;
      margin-bottom: 18px;
    }

    /* 服务卡片网格 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .service-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .service-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      transition: transform 0.4s;
    }
    .service-card:hover .service-img {
      transform: scale(1.03);
    }
    .service-body {
      padding: 22px 20px;
    }
    .service-body h3 {
      font-size: 1.4rem;
      font-weight: 600;
      margin-bottom: 10px;
    }

    /* 数据深色条 */
    .stats-band {
      background: #0F172A;
      padding: 70px 0;
      color: white;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
      text-align: center;
    }
    .stat-number {
      font-size: 3.2rem;
      font-weight: 800;
      color: var(--color-accent);
    }
    .stat-label {
      color: #CBD5E1;
      font-size: 1rem;
    }

    /* 案例横向滚动 */
    .case-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 12px;
      scroll-snap-type: x mandatory;
    }
    .case-card {
      flex: 0 0 280px;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      scroll-snap-align: start;
    }
    .case-img {
      height: 180px;
      background-size: cover;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: white;
      border-radius: 12px;
      margin-bottom: 16px;
      border-left: 4px solid var(--color-accent);
      transition: 0.2s;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 24px 20px;
      color: var(--color-text-soft);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA 底部 */
    .cta-bottom {
      background: #1A0A2E;
      color: white;
      padding: 80px 0;
      text-align: center;
    }

    /* 页脚 */
    .footer {
      background: #0F172A;
      color: #CBD5E1;
      padding: 50px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }

    @media (max-width: 1024px) {
      .advantages-grid, .service-grid { grid-template-columns: repeat(2, 1fr); }
      .stats-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 768px) {
      .nav-links, .nav .btn-primary { display: none; }
      .hamburger { display: flex; }
      .hero h1 { font-size: 2.2rem; }
      .advantages-grid, .service-grid { grid-template-columns: 1fr; }
      .hero-content { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; }
    }

    @media (max-width: 520px) {
      .stats-grid { grid-template-columns: 1fr; }
    }