/* roulang page: index */
:root {
      --bg-deep: #0A0F1E;
      --bg-card: rgba(255, 255, 255, 0.03);
      --border-light: rgba(255, 255, 255, 0.08);
      --text-primary: #FFFFFF;
      --text-secondary: rgba(255, 255, 255, 0.7);
      --text-muted: rgba(255, 255, 255, 0.4);
      --cyan: #00E5FF;
      --cyan-dark: #0099FF;
      --energy: #FF4D00;
      --radius-lg: 24px;
      --radius-md: 16px;
      --radius-sm: 12px;
      --shadow-glow: 0 0 25px rgba(0, 229, 255, 0.5);
      --shadow-card: 0 20px 40px rgba(0, 0, 0, 0.6);
      --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-mono: "Inter", "Roboto", sans-serif;
      --font-number: "DIN Alternate", "Oswald", sans-serif;
    }

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

    body {
      font-family: var(--font-sans);
      background: radial-gradient(circle at 30% 10%, #1A2035, #0A0F1E 80%);
      color: var(--text-primary);
      line-height: 1.6;
      overflow-x: hidden;
      position: relative;
    }

    body::before {
      content: "";
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: 
        linear-gradient(rgba(0, 229, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 229, 255, 0.02) 1px, transparent 1px);
      background-size: 60px 60px;
      pointer-events: none;
      z-index: 0;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
      position: relative;
      z-index: 2;
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(10, 15, 30, 0.75);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.06);
      z-index: 100;
      transition: var(--transition);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 80px;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--text-primary);
      text-decoration: none;
      letter-spacing: 1px;
      position: relative;
    }

    .logo i {
      font-size: 2.2rem;
      color: var(--cyan);
      text-shadow: 0 0 15px var(--cyan);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-link {
      color: var(--text-secondary);
      text-decoration: none;
      font-weight: 500;
      font-size: 1rem;
      transition: var(--transition);
      position: relative;
      padding: 6px 0;
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--cyan);
      box-shadow: 0 0 15px var(--cyan);
      transition: width 0.3s ease;
    }

    .nav-link:hover {
      color: #ffffff;
    }

    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }

    .btn-primary {
      background: linear-gradient(135deg, #00E5FF, #0099FF);
      border: none;
      padding: 12px 28px;
      border-radius: 50px;
      font-weight: 700;
      font-size: 1rem;
      color: #0A0F1E;
      cursor: pointer;
      box-shadow: 0 4px 20px rgba(0, 229, 255, 0.4);
      transition: var(--transition);
      text-decoration: none;
      display: inline-block;
      letter-spacing: 0.5px;
    }

    .btn-primary:hover {
      transform: scale(1.04);
      box-shadow: 0 0 30px rgba(0, 229, 255, 0.7);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid rgba(0, 229, 255, 0.6);
      padding: 12px 28px;
      border-radius: 50px;
      font-weight: 600;
      color: var(--cyan);
      cursor: pointer;
      transition: var(--transition);
      text-decoration: none;
    }

    .btn-outline:hover {
      background: rgba(0, 229, 255, 0.1);
      border-color: var(--cyan);
      box-shadow: 0 0 18px rgba(0, 229, 255, 0.3);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      background: transparent;
      border: none;
    }

    .hamburger span {
      width: 28px;
      height: 2.5px;
      background: var(--text-primary);
      border-radius: 5px;
      transition: var(--transition);
    }

    @media (max-width: 1024px) {
      .nav-links {
        gap: 20px;
      }
    }

    @media (max-width: 768px) {
      .hamburger {
        display: flex;
      }
      .nav-links {
        position: fixed;
        top: 80px;
        left: 0;
        width: 100%;
        background: rgba(10, 15, 30, 0.95);
        backdrop-filter: blur(25px);
        flex-direction: column;
        padding: 32px;
        gap: 24px;
        transform: translateY(-150%);
        transition: transform 0.4s ease;
        border-bottom: 1px solid rgba(255,255,255,0.1);
      }
      .nav-links.active {
        transform: translateY(0);
      }
    }

    /* Hero */
    .hero {
      padding: 160px 0 100px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      position: relative;
    }

    .hero-content {
      flex: 1;
    }

    .hero h1 {
      font-size: 4rem;
      font-weight: 900;
      line-height: 1.2;
      background: linear-gradient(to right, #fff, #b0f0ff);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      margin-bottom: 24px;
      text-shadow: 0 0 30px rgba(0,229,255,0.2);
    }

    .hero-sub {
      font-size: 1.25rem;
      color: var(--text-secondary);
      margin-bottom: 40px;
      max-width: 550px;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .hero-visual {
      flex: 1;
      position: relative;
      min-height: 400px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-lg);
      box-shadow: 0 20px 50px rgba(0,0,0,0.7);
      display: flex;
      align-items: flex-end;
      overflow: hidden;
    }

    .hero-visual::after {
      content: "";
      position: absolute;
      inset: 0;
      background: linear-gradient(0deg, rgba(10,15,30,0.7) 0%, transparent 60%);
    }

    @media (max-width: 992px) {
      .hero {
        flex-direction: column;
        padding: 130px 24px 60px;
      }
      .hero h1 {
        font-size: 2.8rem;
      }
    }

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

    .section-title {
      font-size: 2.6rem;
      font-weight: 700;
      margin-bottom: 16px;
      text-align: center;
    }

    .section-sub {
      color: var(--text-secondary);
      text-align: center;
      max-width: 650px;
      margin: 0 auto 60px;
    }

    /* 服务卡片 错落网格 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .service-card {
      background: var(--bg-card);
      backdrop-filter: blur(18px);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 40px 28px;
      transition: var(--transition);
      position: relative;
      overflow: hidden;
    }

    .service-card:nth-child(2) {
      margin-top: -20px;
    }

    .service-card:nth-child(3) {
      margin-top: 20px;
    }

    .service-card:hover {
      background: rgba(255, 255, 255, 0.07);
      border-color: var(--cyan);
      transform: translateY(-10px);
      box-shadow: 0 25px 45px rgba(0,0,0,0.8);
    }

    .card-icon {
      font-size: 2.8rem;
      color: var(--cyan);
      margin-bottom: 24px;
      text-shadow: 0 0 18px var(--cyan);
    }

    .service-card h3 {
      font-size: 1.7rem;
      margin-bottom: 14px;
    }

    /* 数据板块 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
      text-align: center;
    }

    .stat-item {
      background: rgba(255,255,255,0.02);
      border-radius: var(--radius-md);
      padding: 36px 16px;
      border: 1px solid transparent;
      transition: var(--transition);
    }

    .stat-item:hover {
      border-color: var(--cyan);
    }

    .stat-number {
      font-family: var(--font-number);
      font-size: 3.4rem;
      font-weight: 800;
      background: linear-gradient(135deg, var(--cyan), #fff);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
    }

    .case-card {
      position: relative;
      border-radius: var(--radius-lg);
      overflow: hidden;
      height: 300px;
      background-size: cover;
      background-position: center;
    }

    .case-info {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      padding: 32px;
      background: linear-gradient(transparent, rgba(0,0,0,0.85));
    }

    /* FAQ */
    .faq-item {
      background: rgba(255,255,255,0.03);
      border: 1px solid rgba(255,255,255,0.05);
      border-radius: var(--radius-sm);
      margin-bottom: 16px;
      padding: 20px 24px;
      cursor: pointer;
      transition: var(--transition);
    }

    .faq-item:hover {
      border-color: rgba(0,229,255,0.3);
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 1.2rem;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
      margin-top: 0;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 16px;
    }

    footer {
      background: #050812;
      padding: 60px 0 30px;
      border-top: 1px solid rgba(255,255,255,0.05);
    }

    @media (max-width: 768px) {
      .service-grid, .stats-grid, .case-grid {
        grid-template-columns: 1fr;
      }
      .service-card:nth-child(2), .service-card:nth-child(3) {
        margin-top: 0;
      }
    }