/* roulang page: index */
:root {
      --primary: #0AEFFF;
      --secondary: #0B0E14;
      --accent: #FF4D2E;
      --bg-dark: #131720;
      --card-bg: #1A1E28;
      --text-main: #E8ECF1;
      --text-muted: #8B93A5;
      --text-white: #FFFFFF;
      --border-color: #232836;
      --shadow-card: 0 4px 24px rgba(0,0,0,0.4);
      --shadow-glow: 0 8px 40px rgba(10,239,255,0.15);
      --shadow-accent: 0 0 24px rgba(255,77,46,0.5);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-cn: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-num: "Inter", "DIN Alternate", "Rajdhani", sans-serif;
      --transition: 0.3s ease;
    }

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

    body {
      background-color: var(--bg-dark);
      color: var(--text-main);
      font-family: var(--font-cn);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(11, 14, 20, 0.92);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(10, 239, 255, 0.15);
      z-index: 1000;
      transition: var(--transition);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--text-white);
      text-decoration: none;
      letter-spacing: 1px;
    }
    .logo i {
      color: var(--primary);
      font-size: 2rem;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 36px;
    }
    .nav-link {
      color: var(--text-muted);
      text-decoration: none;
      font-size: 0.95rem;
      font-weight: 500;
      position: relative;
      transition: color 0.25s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .btn-nav {
      background: var(--accent);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      text-decoration: none;
      transition: all 0.25s;
      box-shadow: 0 4px 12px rgba(255,77,46,0.3);
    }
    .btn-nav:hover {
      background: #ff6a4a;
      box-shadow: var(--shadow-accent);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
    }
    .hamburger span {
      display: block;
      width: 26px;
      height: 2px;
      background: var(--text-white);
      transition: 0.25s;
    }
    .hamburger span:last-child {
      width: 18px;
      align-self: flex-end;
    }

    /* 移动端导航抽屉 */
    .mobile-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--secondary);
      backdrop-filter: blur(20px);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      transform: translateX(100%);
      transition: transform 0.4s ease;
      z-index: 999;
    }
    .mobile-nav.active {
      transform: translateX(0);
    }
    .mobile-nav a {
      color: var(--text-muted);
      font-size: 1.5rem;
      text-decoration: none;
      font-weight: 600;
    }
    .mobile-nav .btn-nav {
      margin-top: 20px;
      font-size: 1.2rem;
      padding: 14px 40px;
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 64px 0;
      }
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-white);
      display: flex;
      align-items: center;
      gap: 16px;
    }
    .section-title::before {
      content: '';
      width: 4px;
      height: 32px;
      background: var(--primary);
      display: inline-block;
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 1.1rem;
      margin-bottom: 48px;
    }

    /* 按钮系统 */
    .btn-primary {
      background: var(--primary);
      color: var(--secondary);
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      display: inline-block;
      transition: all 0.25s;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: #3DF7FF;
      box-shadow: 0 0 28px rgba(10,239,255,0.5);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      transition: 0.25s;
    }
    .btn-outline:hover {
      background: rgba(10,239,255,0.08);
      box-shadow: 0 0 18px rgba(10,239,255,0.3);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: 0.25s;
    }
    .btn-accent:hover {
      background: #ff6a4a;
      box-shadow: var(--shadow-accent);
    }

    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      min-height: 100vh;
      background: radial-gradient(circle at 30% 40%, rgba(10,239,255,0.08) 0%, var(--secondary) 80%);
      position: relative;
      overflow: hidden;
    }
    .hero-content {
      flex: 1;
      z-index: 2;
    }
    .hero h1 {
      font-size: 3.5rem;
      font-weight: 700;
      line-height: 1.2;
      color: white;
      margin-bottom: 24px;
    }
    .hero h1 span {
      color: var(--primary);
    }
    .hero p {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin-bottom: 40px;
    }
    .hero-cta {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1;
      position: relative;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero-visual img {
      max-width: 90%;
      border-radius: 24px;
      box-shadow: 0 0 50px rgba(10,239,255,0.2);
      border: 1px solid rgba(10,239,255,0.3);
    }
    @media (max-width: 992px) {
      .hero {
        flex-direction: column;
        text-align: center;
        padding-top: 100px;
      }
      .hero h1 {
        font-size: 2.4rem;
      }
      .hero-visual {
        margin-top: 40px;
      }
    }

    /* 卡片网格 */
    .grid-3, .grid-4 {
      display: grid;
      gap: 32px;
    }
    .grid-4 {
      grid-template-columns: repeat(4, 1fr);
    }
    .grid-3 {
      grid-template-columns: repeat(3, 1fr);
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      border: 1px solid var(--border-color);
      transition: all 0.3s ease;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-glow);
      border-color: rgba(10,239,255,0.4);
    }
    .card i {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 20px;
    }
    .card h3 {
      font-size: 1.4rem;
      margin-bottom: 12px;
      color: white;
    }
    .service-card img {
      width: 100%;
      height: 180px;
      object-fit: cover;
      border-radius: 8px;
      margin-bottom: 16px;
    }
    .tag {
      background: var(--accent);
      color: white;
      padding: 4px 12px;
      border-radius: var(--radius-tag);
      font-size: 0.8rem;
      font-weight: 600;
      display: inline-block;
      margin-bottom: 8px;
    }

    /* 数据区 */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
    }
    .stat-item {
      font-size: 4rem;
      font-weight: 800;
      color: var(--primary);
      font-family: var(--font-num);
    }
    .stat-label {
      color: var(--text-muted);
      margin-top: 8px;
    }

    /* 案例横向滚动 */
    .case-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 24px;
      scrollbar-width: thin;
    }
    .case-card {
      min-width: 320px;
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--border-color);
    }
    .case-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }

    /* 解决方案交替 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-img {
      flex: 1;
    }
    .solution-img img {
      width: 100%;
      border-radius: 16px;
      border: 1px solid var(--border-color);
    }
    .solution-text {
      flex: 1;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-color);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-muted);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* 页脚 */
    footer {
      background: var(--secondary);
      padding: 60px 0 30px;
      color: var(--text-muted);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    @media (max-width: 768px) {
      .grid-4, .grid-3 {
        grid-template-columns: 1fr;
      }
      .nav-menu {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .stats-grid {
        gap: 32px;
      }
      .solution-row, .solution-row.reverse {
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }