/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent-red: #FF3C38;
      --accent-cyan: #00F0FF;
      --bg-light: #F5F5F7;
      --card-white: #FFFFFF;
      --deep-bg: #141832;
      --text-dark: #1E1E2F;
      --text-muted: #6B6B7A;
      --border-light: #E5E5E7;
      --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.06);
      --shadow-hover: 0 12px 32px rgba(0, 0, 0, 0.12);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --font-title: 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --font-number: 'Inter', 'SF Pro Display', sans-serif;
      --transition: 0.3s ease;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.8;
      font-weight: 400;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(10, 14, 39, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      z-index: 1000;
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      transition: background 0.3s ease;
    }

    .header.scrolled {
      background: rgba(10, 14, 39, 0.96);
      border-bottom: 1px solid rgba(255, 255, 255, 0.15);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-family: var(--font-number);
      font-weight: 900;
      font-size: 26px;
      letter-spacing: -0.5px;
      color: white;
      display: flex;
      align-items: center;
      gap: 4px;
    }
    .logo span {
      color: var(--accent-cyan);
    }

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

    .nav-links a {
      color: rgba(255, 255, 255, 0.9);
      font-weight: 500;
      font-size: 15px;
      position: relative;
      padding: 6px 0;
      transition: color 0.2s;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: all 0.25s ease;
      transform: translateX(-50%);
    }

    .nav-links a:hover {
      color: white;
    }
    .nav-links a:hover::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--accent-red);
      color: white;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      border: none;
      cursor: pointer;
      transition: all 0.25s ease;
      display: inline-block;
      font-size: 15px;
      letter-spacing: 0.3px;
      box-shadow: 0 4px 12px rgba(255, 60, 56, 0.3);
    }

    .btn-primary:hover {
      background: #D62E2A;
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(255, 60, 56, 0.5);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: white;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      transition: 0.25s ease;
      cursor: pointer;
      font-size: 15px;
    }
    .btn-outline:hover {
      background: rgba(0, 240, 255, 0.1);
      transform: translateY(-2px);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }

    /* 移动端菜单 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: #0A0E27;
      padding: 32px;
      flex-direction: column;
      gap: 28px;
      z-index: 999;
      border-top: 1px solid rgba(255,255,255,0.1);
    }
    .mobile-menu a {
      color: white;
      font-size: 20px;
      font-weight: 500;
    }
    .mobile-menu .btn-primary {
      text-align: center;
      width: fit-content;
    }

    /* 区块通用 */
    section {
      padding: 100px 0;
    }

    .section-title {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 36px;
      line-height: 1.3;
      margin-bottom: 16px;
      color: var(--primary);
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 18px;
      max-width: 680px;
      margin: 0 auto 48px;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0A0E27 0%, #141832 100%);
      color: white;
      padding: 140px 0 100px;
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: "";
      position: absolute;
      inset: 0;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.2;
      pointer-events: none;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 1;
    }
    .hero h1 {
      font-family: var(--font-title);
      font-weight: 900;
      font-size: 52px;
      line-height: 1.2;
      margin-bottom: 24px;
      color: white;
    }
    .hero h1 span {
      color: var(--accent-cyan);
    }
    .hero-desc {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      margin-bottom: 36px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-visual img {
      max-height: 360px;
      border-radius: var(--radius-lg);
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      margin-top: 40px;
    }
    .feature-card {
      background: var(--card-white);
      padding: 36px 32px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      display: flex;
      gap: 28px;
      transition: all 0.3s ease;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .feature-num {
      font-family: var(--font-number);
      font-weight: 900;
      font-size: 64px;
      color: var(--accent-cyan);
      line-height: 1;
      opacity: 0.9;
    }
    .feature-content h3 {
      font-size: 22px;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .feature-content p {
      color: var(--text-muted);
      font-size: 15px;
    }

    /* 数据深色区块 */
    .stats {
      background: #0A0E27;
      color: white;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
      text-align: center;
    }
    .stat-item .number {
      font-family: var(--font-number);
      font-weight: 900;
      font-size: 48px;
      color: var(--accent-cyan);
    }
    .stat-item .label {
      font-size: 16px;
      color: rgba(255,255,255,0.7);
      margin-top: 8px;
    }
    .stat-divider {
      width: 40px;
      height: 3px;
      background: var(--accent-red);
      margin: 12px auto 0;
    }

    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: 0.3s;
    }
    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 200px;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: 0.4s ease;
    }
    .case-card:hover .case-img img {
      transform: scale(1.05);
    }
    .case-info {
      padding: 20px 24px;
    }
    .case-tag {
      font-size: 13px;
      color: var(--accent-red);
      font-weight: 600;
      margin-bottom: 8px;
    }

    /* 解决方案交替 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-text {
      flex: 1;
    }
    .solution-text h3 {
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .solution-list {
      list-style: none;
      margin: 20px 0;
    }
    .solution-list li::before {
      content: "●";
      color: var(--accent-cyan);
      margin-right: 10px;
    }
    .solution-img {
      flex: 1;
      border-radius: var(--radius-lg);
      overflow: hidden;
    }

    /* FAQ */
    .faq-item {
      background: white;
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      padding-left: 12px;
      border-left: 4px solid var(--accent-cyan);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      padding-left: 28px;
      color: var(--text-muted);
    }
    .faq-answer.open {
      max-height: 200px;
      margin-top: 12px;
    }

    .cta-band {
      background: #0A0E27;
      text-align: center;
      padding: 80px 0;
      color: white;
    }

    .footer {
      background: #0A0E27;
      color: rgba(255,255,255,0.7);
      padding: 60px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    @media (max-width: 1024px) {
      .features-grid, .cases-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero h1 { font-size: 36px; }
      .features-grid, .cases-grid, .stats-grid {
        grid-template-columns: 1fr;
      }
      .solution-row {
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      section {
        padding: 70px 0;
      }
    }