/* roulang page: index */
:root {
      --primary: #0A1F33;
      --primary-light: #0B2B45;
      --secondary: #00B4D8;
      --accent: #FF6B35;
      --accent-hover: #E55A2B;
      --bg: #F5F7FA;
      --white: #FFFFFF;
      --text-title: #1E293B;
      --text-body: #475569;
      --text-muted: #94A3B8;
      --border-light: #E2E8F0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-sm: 0 4px 20px rgba(10,31,51,0.06);
      --shadow-md: 0 12px 32px rgba(10,31,51,0.12);
      --shadow-lg: 0 20px 40px rgba(10,31,51,0.15);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Inter", "SF Pro Display", system-ui, sans-serif;
      --transition: all 0.25s ease;
      --container-max: 1280px;
      --nav-height: 72px;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      text-rendering: optimizeLegibility;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: var(--transition);
      outline: none;
    }

    button:focus-visible, a:focus-visible, .btn:focus-visible {
      outline: 3px solid rgba(0,180,216,0.5);
      outline-offset: 2px;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .nav {
      position: sticky;
      top: 0;
      z-index: 100;
      background: var(--white);
      height: var(--nav-height);
      display: flex;
      align-items: center;
      box-shadow: 0 2px 12px rgba(10,31,51,0.05);
      backdrop-filter: blur(10px);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.5px;
      white-space: nowrap;
    }
    .logo i {
      color: var(--secondary);
      margin-right: 6px;
      font-size: 1.6rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-title);
      position: relative;
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--secondary);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--secondary);
      transition: width 0.2s ease;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      box-shadow: 0 4px 10px rgba(255,107,53,0.25);
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(255,107,53,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--primary);
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .mobile-menu {
        display: none;
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 32px 24px;
        gap: 24px;
        box-shadow: 0 20px 40px rgba(0,0,0,0.1);
        z-index: 99;
      }
      .mobile-menu.open {
        display: flex;
      }
      .mobile-menu a {
        font-size: 1.5rem;
        font-weight: 600;
        color: var(--text-title);
        text-align: center;
      }
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
      color: white;
      padding: 80px 0 100px;
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.25;
      mix-blend-mode: overlay;
    }
    .hero-content {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 1;
    }
    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      margin-bottom: 20px;
      color: white;
    }
    .hero .subtitle {
      font-size: 1.2rem;
      opacity: 0.9;
      margin-bottom: 32px;
      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: 24px;
      box-shadow: 0 25px 50px rgba(0,0,0,0.3);
    }
    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
        text-align: center;
      }
      .hero h1 {
        font-size: 2.2rem;
      }
      .hero-buttons {
        justify-content: center;
      }
    }

    /* 通用板块 */
    .section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--text-title);
      text-align: center;
      margin-bottom: 16px;
    }
    .section-sub {
      text-align: center;
      color: var(--text-muted);
      max-width: 600px;
      margin: 0 auto 60px;
    }

    /* 价值主张 */
    .value-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .value-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: var(--transition);
    }
    .value-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .value-icon {
      font-size: 2.5rem;
      color: var(--secondary);
      margin-bottom: 20px;
    }
    .value-card h3 {
      font-size: 1.3rem;
      margin-bottom: 12px;
    }

    /* 功能分组 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .feature-row.reverse {
      flex-direction: row-reverse;
    }
    .feature-img {
      flex: 1;
      border-radius: 20px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .feature-text {
      flex: 1;
    }
    .tag {
      display: inline-block;
      background: rgba(0,180,216,0.1);
      color: var(--secondary);
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
      margin-bottom: 12px;
    }

    /* 场景卡片 */
    .scenario-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .scenario-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .scenario-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
    }
    .scenario-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .scenario-content {
      padding: 20px;
    }

    /* 案例 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 20px;
      scrollbar-width: thin;
    }
    .case-card {
      min-width: 280px;
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      flex-shrink: 0;
    }

    /* 价格 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .pricing-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      text-align: center;
      border: 2px solid transparent;
    }
    .pricing-card.featured {
      border-color: var(--primary);
      transform: scale(1.03);
      box-shadow: var(--shadow-md);
      position: relative;
    }
    .popular-badge {
      background: var(--secondary);
      color: white;
      font-size: 0.75rem;
      padding: 4px 14px;
      border-radius: 20px;
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
    }

    /* FAQ */
    .faq-item {
      background: var(--white);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      box-shadow: var(--shadow-sm);
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      padding: 0 24px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* 尾屏CTA */
    .cta-section {
      background: var(--secondary);
      color: white;
      text-align: center;
      padding: 80px 24px;
    }

    /* 页脚 */
    .footer {
      background: var(--primary);
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
    }
    @media (max-width: 768px) {
      .value-grid, .scenario-grid, .pricing-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .feature-row {
        flex-direction: column;
      }
    }