/* roulang page: index */
:root {
      --primary: #0A0E17;
      --accent: #00F0FF;
      --danger: #FF3C5A;
      --bg-soft: #FAFAFC;
      --text-main: #0A0E17;
      --text-body: #2C3A4B;
      --text-muted: #6B7B8D;
      --border-light: #E8ECF1;
      --shadow-sm: 0 4px 20px rgba(10,14,23,0.06);
      --shadow-hover: 0 12px 32px rgba(10,14,23,0.12);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-btn: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-mono: "Inter", "SF Pro Display", system-ui, sans-serif;
      --transition-smooth: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

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

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

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    h1, h2, h3, h4 {
      color: var(--text-main);
      font-weight: 600;
    }

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

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

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(12px);
      z-index: 1000;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: var(--transition-smooth);
    }

    .header.scrolled {
      border-bottom-color: var(--border-light);
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
    }

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

    .logo {
      font-weight: 700;
      font-size: 1.8rem;
      color: var(--primary);
      letter-spacing: 1px;
      position: relative;
      display: inline-block;
    }

    .logo::after {
      content: "";
      position: absolute;
      left: 0;
      bottom: -6px;
      width: 60%;
      height: 3px;
      background: var(--accent);
      border-radius: 4px;
      transition: width 0.2s ease;
    }

    .logo:hover::after {
      width: 100%;
    }

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

    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-body);
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }

    .nav-link::after {
      content: "";
      position: absolute;
      left: 50%;
      bottom: -4px;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: 0.25s ease;
      transform: translateX(-50%);
    }

    .nav-link:hover {
      color: var(--accent);
    }

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

    .btn-nav {
      background: var(--accent);
      color: var(--primary);
      font-weight: 600;
      padding: 8px 20px;
      border-radius: 20px;
      font-size: 14px;
      letter-spacing: 0.3px;
      transition: var(--transition-smooth);
      box-shadow: 0 4px 10px rgba(0,240,255,0.2);
    }

    .btn-nav:hover {
      background: #00D4E0;
      box-shadow: 0 0 0 4px rgba(0,240,255,0.35);
      transform: translateY(-1px);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 26px;
      color: var(--primary);
      cursor: pointer;
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        height: 100vh;
        background: var(--bg-soft);
        flex-direction: column;
        padding: 100px 32px;
        gap: 28px;
        transition: right 0.4s ease;
        box-shadow: -8px 0 24px rgba(0,0,0,0.08);
      }
      .nav-links.active {
        right: 0;
      }
      .menu-toggle {
        display: block;
        z-index: 1100;
      }
    }

    .hero {
      min-height: 100vh;
      background: var(--primary);
      display: flex;
      align-items: center;
      position: relative;
      padding: 0 24px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
    }

    .hero-content {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      gap: 40px;
    }

    .hero-text {
      flex: 1;
    }

    .hero h1 {
      font-size: 56px;
      font-weight: 700;
      line-height: 1.1;
      color: white;
      margin-bottom: 24px;
    }

    .hero-sub {
      font-size: 18px;
      color: #B0BEC5;
      margin-bottom: 40px;
      max-width: 480px;
    }

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

    .btn-primary {
      background: var(--accent);
      color: var(--primary);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      transition: var(--transition-smooth);
      display: inline-block;
    }

    .btn-primary:hover {
      background: #00D4E0;
      box-shadow: 0 0 0 4px rgba(0,240,255,0.30);
    }

    .btn-outline-white {
      border: 1px solid white;
      color: white;
      background: transparent;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition-smooth);
    }

    .btn-outline-white:hover {
      background: white;
      color: var(--primary);
    }

    .hero-visual {
      flex: 1;
      display: flex;
      justify-content: flex-end;
    }

    .hero-visual img {
      max-width: 90%;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    }

    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
        text-align: left;
      }
      .hero h1 {
        font-size: 38px;
      }
      .hero-visual img {
        max-width: 100%;
        margin-top: 32px;
      }
    }

    section {
      padding: 140px 0;
    }

    .section-title {
      font-size: 36px;
      font-weight: 600;
      margin-bottom: 24px;
    }

    .text-muted {
      color: var(--text-muted);
    }

    .advantages-grid {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }

    .adv-highlight {
      display: flex;
      gap: 48px;
      background: white;
      border-radius: var(--radius-lg);
      padding: 32px;
      align-items: center;
      border: 1px solid var(--border-light);
    }

    .adv-cards {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }

    .card {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-lg);
      padding: 32px;
      transition: var(--transition-smooth);
      box-shadow: var(--shadow-sm);
    }

    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--accent);
    }

    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .scene-row {
      display: flex;
      gap: 48px;
      align-items: center;
      margin-bottom: 64px;
    }

    .scene-row.reverse {
      flex-direction: row-reverse;
    }

    .case-cards {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .pricing-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 40px 28px;
      text-align: center;
      border: 1px solid var(--border-light);
      transition: var(--transition-smooth);
    }

    .pricing-card.popular {
      border: 2px solid var(--accent);
      position: relative;
    }

    .badge {
      background: var(--accent);
      color: var(--primary);
      padding: 4px 14px;
      border-radius: 20px;
      font-weight: 600;
      font-size: 14px;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
    }

    .faq-question {
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
    }

    .cta-final {
      background: var(--primary);
      text-align: center;
      padding: 100px 24px;
      color: white;
    }

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

    @media (max-width: 768px) {
      .features-grid, .case-cards, .pricing-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .adv-highlight, .scene-row {
        flex-direction: column;
      }
    }