/* roulang page: index */
:root {
      --primary: #0A6EFF;
      --primary-dark: #0052CC;
      --secondary: #00C48C;
      --accent: #FF6B35;
      --bg: #F8FAFC;
      --white: #FFFFFF;
      --text: #1E293B;
      --text-muted: #64748B;
      --border: #E2E8F0;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.12);
      --radius: 16px;
      --radius-sm: 12px;
      --transition: 0.3s ease;
      --max-width: 1200px;
      --nav-height: 72px;
    }

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

    body {
      font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background: var(--bg);
      color: var(--text);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    a {
      text-decoration: none;
      color: inherit;
    }

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

    button, .btn {
      cursor: pointer;
      border: none;
      background: none;
      font-family: inherit;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition);
      font-weight: 600;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(10px);
      box-shadow: 0 2px 20px rgba(0,0,0,0.04);
      z-index: 1000;
      display: flex;
      align-items: center;
    }

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

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo span {
      background: var(--primary);
      color: white;
      width: 36px;
      height: 36px;
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.3rem;
    }

    .nav-links {
      display: flex;
      gap: 2.2rem;
      font-weight: 500;
      color: var(--text-muted);
    }

    .nav-links a {
      transition: color 0.2s;
      position: relative;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }

    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 3px;
      background: var(--primary);
      border-radius: 3px;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      width: 28px;
    }

    .hamburger span {
      height: 3px;
      background: var(--text);
      border-radius: 3px;
      transition: var(--transition);
    }

    .mobile-menu {
      display: none;
    }

    /* 板块间距 */
    section {
      padding: 100px 0;
    }

    /* Hero */
    .hero {
      padding-top: calc(var(--nav-height) + 60px);
      background: var(--bg);
      background-image: radial-gradient(circle at 20% 30%, rgba(10,110,255,0.03) 0%, transparent 40%);
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }

    .hero-text h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 1.2rem;
      color: var(--text);
    }

    .hero-highlight {
      color: var(--primary);
    }

    .hero-text p {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin-bottom: 2rem;
    }

    .btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-size: 1.1rem;
      box-shadow: 0 8px 18px rgba(10,110,255,0.3);
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
      box-shadow: 0 12px 24px rgba(0,82,204,0.4);
    }

    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 32px;
      border-radius: var(--radius-sm);
      font-size: 1.1rem;
      background: transparent;
    }

    .btn-outline:hover {
      background: rgba(10,110,255,0.06);
    }

    .hero-image {
      background: white;
      border-radius: 32px;
      box-shadow: var(--shadow-md);
      overflow: hidden;
      display: flex;
      justify-content: center;
      padding: 20px;
    }

    /* 标题统一 */
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      text-align: center;
      margin-bottom: 16px;
    }

    .section-sub {
      text-align: center;
      color: var(--text-muted);
      margin-bottom: 60px;
      font-size: 1.1rem;
    }

    /* 核心优势 3列 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .adv-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      text-align: center;
    }

    .adv-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .adv-icon {
      background: rgba(10,110,255,0.1);
      width: 64px;
      height: 64px;
      border-radius: 20px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      font-size: 2rem;
      color: var(--primary);
    }

    .adv-card h3 {
      font-size: 1.4rem;
      margin-bottom: 12px;
    }

    /* 功能分组卡片 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .feature-card {
      background: white;
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
    }

    .feature-list {
      list-style: none;
      margin-top: 20px;
    }

    .feature-list li {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 12px;
      color: var(--text-muted);
    }

    .feature-list li::before {
      content: "✓";
      color: var(--secondary);
      font-weight: bold;
    }

    .inline-link {
      color: var(--primary);
      font-weight: 600;
      margin-top: 16px;
      display: inline-block;
    }

    /* 场景卡片横排 */
    .scene-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .scene-card {
      background: white;
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .scene-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .scene-img {
      height: 200px;
      background: #eef2f6;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .scene-content {
      padding: 24px;
    }

    /* 案例非对称 */
    .case-block {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
      background: white;
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      margin-bottom: 30px;
    }

    .case-data {
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--primary);
    }

    /* 步骤 */
    .steps-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }

    .step-item {
      background: white;
      padding: 32px 16px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
    }

    .step-num {
      background: var(--primary);
      color: white;
      width: 48px;
      height: 48px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      font-weight: 700;
      font-size: 1.4rem;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: white;
      border-radius: var(--radius-sm);
      margin-bottom: 16px;
      box-shadow: var(--shadow-sm);
      overflow: hidden;
    }

    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      transition: 0.2s;
    }

    .faq-question:hover {
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      padding: 0 24px;
      background: #f9fafb;
      color: var(--text-muted);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 20px 24px;
    }

    .arrow {
      transition: 0.3s;
    }

    .faq-item.active .arrow {
      transform: rotate(180deg);
    }

    /* 最终CTA */
    .cta-band {
      background: linear-gradient(135deg, #0A6EFF, #0052CC);
      border-radius: 32px;
      padding: 70px 40px;
      text-align: center;
      color: white;
    }

    .cta-band h2 {
      font-size: 2.2rem;
    }

    .btn-white {
      background: white;
      color: var(--primary);
      padding: 14px 40px;
      border-radius: 40px;
      font-weight: 700;
      margin-top: 24px;
    }

    /* 页脚 */
    .footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-bottom {
      text-align: center;
      border-top: 1px solid #334155;
      padding-top: 24px;
      font-size: 0.9rem;
    }

    @media (max-width: 1024px) {
      .hero-grid, .case-block {
        grid-template-columns: 1fr;
        gap: 40px;
      }
      .advantages-grid, .features-grid, .scene-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .steps-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-menu {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.96);
        backdrop-filter: blur(12px);
        padding: 30px;
        gap: 24px;
        transform: translateY(-100%);
        transition: 0.3s;
        box-shadow: 0 10px 25px rgba(0,0,0,0.1);
      }
      .mobile-menu.open {
        transform: translateY(0);
      }
      .advantages-grid, .features-grid, .scene-grid {
        grid-template-columns: 1fr;
      }
      .steps-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      h1 {
        font-size: 2rem !important;
      }
    }