/* roulang page: index */
:root {
      --primary: #7B2FF7;
      --primary-dark: #6A1BE0;
      --accent: #00E5FF;
      --accent-light: #00E5FF1A;
      --bg: #F8F9FC;
      --surface: #FFFFFF;
      --dark: #1A1A2E;
      --text: #4A4A5A;
      --text-muted: #8E8E9E;
      --gold: #FFB800;
      --gold-light: #FFC940;
      --card-shadow: 0 4px 24px rgba(26,26,46,0.06);
      --card-shadow-hover: 0 8px 32px rgba(123,47,247,0.12);
      --radius: 16px;
      --radius-sm: 12px;
      --radius-pill: 50px;
      --transition: 0.3s ease;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }

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

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

    /* 导航 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--surface);
      border-bottom: 1px solid rgba(0,0,0,0.04);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
      transition: box-shadow 0.3s;
    }

    #header.scrolled {
      box-shadow: 0 2px 16px rgba(0,0,0,0.04);
    }

    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--dark);
    }

    .logo svg {
      width: 36px;
      height: 36px;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }

    .nav-menu a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text);
      padding: 8px 0;
      position: relative;
      transition: color 0.2s;
    }

    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      font-size: 0.95rem;
      box-shadow: 0 4px 12px rgba(123,47,247,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 6px 18px rgba(123,47,247,0.3);
      transform: translateY(-1px);
    }

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

    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: var(--bg);
        flex-direction: column;
        padding: 80px 32px;
        gap: 32px;
        transition: right 0.3s ease;
        box-shadow: -4px 0 24px rgba(0,0,0,0.1);
      }
      .nav-menu.open {
        right: 0;
      }
      .hamburger {
        display: flex;
        z-index: 1001;
      }
      .btn-primary.desktop-cta {
        display: none;
      }
    }

    @media (min-width: 769px) {
      .hamburger {
        display: none;
      }
    }

    /* Hero */
    #hero {
      margin-top: 72px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      padding: 100px 0;
      display: flex;
      align-items: center;
      min-height: 85vh;
    }
    #hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(26,26,46,0.75) 0%, rgba(26,26,46,0.2) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      color: white;
      max-width: 700px;
    }
    .hero-badge {
      display: inline-block;
      background: rgba(0,229,255,0.2);
      border: 1px solid var(--accent);
      color: var(--accent);
      padding: 6px 18px;
      border-radius: 20px;
      font-size: 0.9rem;
      font-weight: 500;
      margin-bottom: 24px;
    }
    h1 {
      font-size: 3.5rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      color: white;
      letter-spacing: -0.5px;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.85);
      margin-bottom: 32px;
      line-height: 1.7;
    }
    .btn-gold {
      background: var(--gold);
      color: var(--dark);
      font-weight: 700;
      padding: 16px 36px;
      border-radius: var(--radius-pill);
      font-size: 1.1rem;
      display: inline-block;
      box-shadow: 0 8px 20px rgba(255,184,0,0.3);
    }
    .btn-gold:hover {
      background: var(--gold-light);
      transform: scale(1.03);
    }
    .btn-outline-light {
      border: 2px solid white;
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      margin-left: 16px;
      background: transparent;
    }
    .btn-outline-light:hover {
      background: rgba(255,255,255,0.1);
    }

    @media (max-width: 768px) {
      h1 { font-size: 2.2rem; }
      .hero-sub { font-size: 1rem; }
      .btn-outline-light { margin-left: 0; margin-top: 12px; display: block; width: fit-content; }
    }

    section {
      padding: 80px 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    h2 {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--dark);
      margin-bottom: 12px;
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 1.1rem;
    }

    /* 优势 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .advantage-card {
      background: var(--surface);
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }
    .advantage-card:hover {
      box-shadow: var(--card-shadow-hover);
      transform: translateY(-4px);
    }
    .adv-icon {
      width: 56px;
      height: 56px;
      background: rgba(123,47,247,0.1);
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
    }
    .advantage-card h3 {
      font-size: 1.3rem;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--dark);
    }

    @media (max-width: 768px) {
      .grid-3 { grid-template-columns: 1fr; }
      h2 { font-size: 2rem; }
    }

    /* 服务非对称 */
    .services-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .service-card {
      background: var(--surface);
      border-radius: var(--radius);
      display: flex;
      overflow: hidden;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }
    .service-card:hover {
      box-shadow: var(--card-shadow-hover);
      transform: translateY(-3px);
    }
    .service-img {
      width: 35%;
      background-size: cover;
      background-position: center;
    }
    .service-info {
      padding: 28px;
      width: 65%;
    }
    .service-info h3 {
      font-weight: 600;
      font-size: 1.25rem;
      margin-bottom: 8px;
    }
    @media (max-width: 768px) {
      .services-grid { grid-template-columns: 1fr; }
      .service-card { flex-direction: column; }
      .service-img { height: 180px; width: 100%; }
      .service-info { width: 100%; }
    }

    /* 数据 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
    }
    .stat-card {
      background: #F0F1F5;
      border-radius: 20px;
      padding: 32px 16px;
      text-align: center;
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--accent);
    }
    .stat-label {
      color: var(--text-muted);
      margin-top: 4px;
    }
    @media (max-width: 768px) {
      .stats-grid { grid-template-columns: 1fr 1fr; }
    }

    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 24px;
    }
    .case-card {
      background: var(--surface);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--card-shadow-hover);
      transform: translateY(-3px);
    }
    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .case-body {
      padding: 20px;
    }
    @media (max-width: 768px) {
      .cases-grid { grid-template-columns: 1fr; }
    }

    /* FAQ */
    .faq-item {
      background: var(--surface);
      border-radius: var(--radius-sm);
      margin-bottom: 16px;
      box-shadow: var(--card-shadow);
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: none;
      width: 100%;
      text-align: left;
      font-size: 1rem;
    }
    .faq-answer {
      padding: 0 24px 20px;
      display: none;
      color: var(--text);
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA */
    #cta {
      background: var(--primary);
      color: white;
      text-align: center;
      border-radius: 0;
    }
    #cta h2 {
      color: white;
      margin-bottom: 16px;
    }

    footer {
      background: var(--dark);
      color: #ccc;
      padding: 48px 0 24px;
      font-size: 0.9rem;
    }
    .footer-grid {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 24px;
      margin-bottom: 24px;
    }