/* roulang page: index */
/* 设计变量与重置 */
    :root {
      --primary: #FF4D00;
      --primary-light: #FF7A00;
      --secondary: #8A2BE2;
      --dark-bg: #0B0C0E;
      --card-bg: #1A1D23;
      --glass-bg: rgba(26, 29, 35, 0.7);
      --text-body: #E8E8E8;
      --text-muted: #B0B0B0;
      --white: #FFFFFF;
      --border-light: rgba(255,255,255,0.08);
      --border-glow: rgba(138,43,226,0.5);
      --radius-lg: 16px;
      --radius-md: 12px;
      --shadow-glow: 0 0 20px rgba(255,77,0,0.5);
      --font-tech: 'Orbitron', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --font-body: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --max-width: 1280px;
      --section-padding: 100px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--dark-bg);
    }
    body {
      font-family: var(--font-body);
      background: var(--dark-bg);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.3s ease;
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      font-weight: 600;
      transition: all 0.3s ease;
      border: none;
      outline: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      :root {
        --section-padding: 60px;
      }
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: transparent;
      transition: background 0.4s ease, backdrop-filter 0.4s ease, box-shadow 0.4s ease;
      padding: 16px 0;
    }
    .navbar.scrolled {
      background: rgba(11, 12, 14, 0.85);
      backdrop-filter: blur(20px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
      border-bottom: 1px solid rgba(255,77,0,0.15);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-family: var(--font-tech);
      font-weight: 900;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      color: var(--white);
      text-transform: uppercase;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--primary);
      font-weight: 900;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-link {
      font-weight: 500;
      font-size: 1rem;
      color: var(--text-body);
      position: relative;
      padding: 4px 0;
      transition: color 0.3s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.3s ease;
    }
    .nav-link:hover {
      color: var(--white);
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .nav-cta {
      background: linear-gradient(135deg, #FF4D00 0%, #FF7A00 100%);
      color: white;
      padding: 10px 24px;
      border-radius: 40px;
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(255,77,0,0.4);
      font-size: 0.95rem;
      white-space: nowrap;
    }
    .nav-cta:hover {
      box-shadow: var(--shadow-glow);
      transform: translateY(-2px);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      display: block;
      width: 26px;
      height: 2px;
      background: var(--white);
      transition: 0.3s;
      border-radius: 2px;
    }
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        height: 100vh;
        background: #0B0C0E;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 40px;
        transition: right 0.4s ease;
        backdrop-filter: blur(20px);
        z-index: 999;
      }
      .nav-menu.active {
        right: 0;
      }
      .hamburger {
        display: flex;
        z-index: 1001;
      }
      .nav-link {
        font-size: 1.8rem;
      }
      .nav-cta {
        font-size: 1.2rem;
        padding: 14px 32px;
      }
    }

    /* 板块通用 */
    section {
      padding: var(--section-padding) 0;
    }
    .section-title {
      font-family: var(--font-tech);
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--white);
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }
    .section-sub {
      color: var(--text-muted);
      max-width: 700px;
      margin: 0 auto 48px;
      font-size: 1.1rem;
    }
    .text-center {
      text-align: center;
    }
    .gradient-text {
      background: linear-gradient(135deg, #FF4D00, #FF7A00);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    /* Hero */
    .hero {
      position: relative;
      height: 100vh;
      min-height: 700px;
      display: flex;
      align-items: center;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-blend-mode: overlay;
      overflow: hidden;
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(180deg, rgba(11,12,14,0.4) 0%, #0B0C0E 95%);
      z-index: 1;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      margin-top: 40px;
    }
    .hero h1 {
      font-family: var(--font-tech);
      font-size: clamp(3rem, 8vw, 5rem);
      font-weight: 900;
      color: white;
      text-shadow: 0 0 40px rgba(255,77,0,0.5);
      letter-spacing: -0.02em;
      line-height: 1.1;
      margin-bottom: 24px;
    }
    .hero p {
      font-size: 1.3rem;
      color: #E8E8E8;
      max-width: 600px;
      margin-bottom: 40px;
    }
    .btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 20px;
    }
    .btn-primary {
      background: linear-gradient(135deg, #FF4D00 0%, #FF7A00 100%);
      color: white;
      padding: 16px 40px;
      border-radius: 50px;
      font-weight: 700;
      box-shadow: 0 8px 24px rgba(255,77,0,0.45);
      font-size: 1.1rem;
    }
    .btn-primary:hover {
      box-shadow: 0 0 30px rgba(255,77,0,0.8);
      transform: translateY(-3px);
    }
    .btn-outline {
      border: 1px solid rgba(255,255,255,0.35);
      color: white;
      padding: 16px 40px;
      border-radius: 50px;
      font-weight: 600;
      background: transparent;
      backdrop-filter: blur(4px);
    }
    .btn-outline:hover {
      border-color: var(--primary);
      background: rgba(255,77,0,0.1);
      box-shadow: 0 0 18px rgba(255,77,0,0.3);
    }

    /* 服务卡片 - 不等高交错 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
      margin-top: 20px;
    }
    .service-card {
      background: var(--glass-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-lg);
      padding: 32px;
      transition: all 0.4s ease;
      position: relative;
      overflow: hidden;
    }
    .service-card:nth-child(2) {
      grid-row: span 2;
    }
    .service-card:nth-child(3) {
      grid-row: span 1;
    }
    .service-card:hover {
      transform: translateY(-8px);
      border-color: rgba(255,77,0,0.5);
      box-shadow: 0 20px 30px rgba(0,0,0,0.6), 0 0 18px rgba(255,77,0,0.3);
    }
    .service-icon {
      width: 60px;
      height: 60px;
      background: #1A1D23;
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 1.8rem;
      margin-bottom: 20px;
      border: 1px solid rgba(255,77,0,0.2);
    }
    .service-card h3 {
      font-family: var(--font-tech);
      font-size: 1.5rem;
      color: white;
      margin-bottom: 12px;
    }
    .service-card p {
      color: var(--text-muted);
    }

    /* 数据 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-tech);
      font-size: 3rem;
      font-weight: 700;
      background: linear-gradient(135deg, #FF4D00, #8A2BE2);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    @media (max-width: 768px) {
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      border-radius: var(--radius-md);
      overflow: hidden;
      position: relative;
      background: #1A1D23;
      transition: 0.4s;
    }
    .case-card img {
      width: 100%;
      height: 240px;
      object-fit: cover;
      transition: transform 0.5s;
    }
    .case-card:hover img {
      transform: scale(1.05);
    }
    .case-info {
      padding: 20px;
      background: linear-gradient(transparent, #0B0C0E);
    }
    @media (max-width: 768px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-item {
      background: #1A1D23;
      border-radius: 12px;
      margin-bottom: 16px;
      border: 1px solid transparent;
      transition: 0.3s;
    }
    .faq-item.active {
      border-color: var(--border-glow);
      box-shadow: 0 0 15px rgba(138,43,226,0.25);
    }
    .faq-question {
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: #B0B0B0;
      padding: 0 20px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* CTA横幅 */
    .cta-banner {
      background: #0B0C0E radial-gradient(circle at 30% 30%, rgba(255,77,0,0.15), transparent);
      position: relative;
    }
    .particles {
      position: absolute;
      inset: 0;
      pointer-events: none;
    }

    /* 页脚 */
    .footer {
      background: #000;
      border-top: 1px solid var(--primary);
      padding: 60px 0 20px;
    }