/* roulang page: index */
:root {
      --deep-blue: #0A0E27;
      --electric-cyan: #00E5FF;
      --accent-orange: #FF6B35;
      --text-primary: #E8ECF1;
      --text-secondary: #8E9BB5;
      --card-bg: rgba(15, 25, 55, 0.6);
      --card-border: rgba(0, 229, 255, 0.2);
      --glass-blur: blur(12px);
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
      --radius-lg: 16px;
      --radius-md: 12px;
      --transition-smooth: 0.3s ease;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
    }

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

    body {
      font-family: var(--font-heading);
      background-color: var(--deep-blue);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 16px;
      background-image: radial-gradient(circle at 20% 20%, rgba(0, 229, 255, 0.08) 0%, transparent 45%),
                        radial-gradient(circle at 80% 60%, rgba(255, 107, 53, 0.06) 0%, transparent 40%),
                        linear-gradient(180deg, #0A0E27 0%, #0F1635 100%);
      min-height: 100vh;
    }

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

    /* 导航 */
    .nav-bar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 14, 39, 0.75);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0, 229, 255, 0.15);
      transition: background 0.3s ease;
      padding: 0 32px;
    }

    .nav-bar.scrolled {
      background: rgba(10, 14, 39, 0.96);
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      margin: 0 auto;
      height: 72px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 24px;
      font-weight: 700;
      color: #fff;
      text-decoration: none;
      letter-spacing: 1px;
    }

    .logo-icon {
      font-size: 28px;
      color: var(--electric-cyan);
      filter: drop-shadow(0 0 8px var(--electric-cyan));
    }

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

    .nav-link {
      color: var(--text-secondary);
      text-decoration: none;
      font-weight: 500;
      font-size: 16px;
      transition: color 0.2s;
      position: relative;
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--electric-cyan);
    }

    .nav-cta {
      background: transparent;
      border: 1px solid var(--electric-cyan);
      color: var(--electric-cyan);
      padding: 8px 20px;
      border-radius: 30px;
      font-weight: 600;
      text-decoration: none;
      transition: all 0.3s ease;
      margin-left: 8px;
    }

    .nav-cta:hover {
      background: var(--electric-cyan);
      color: #0A0E27;
      box-shadow: 0 0 15px var(--electric-cyan);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }

    .hamburger span {
      width: 25px;
      height: 2px;
      background: var(--text-primary);
      transition: 0.3s;
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(10, 14, 39, 0.98);
        backdrop-filter: blur(25px);
        flex-direction: column;
        padding: 32px;
        gap: 24px;
        align-items: flex-start;
        border-bottom: 1px solid var(--electric-cyan);
      }
      .nav-menu.active {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .nav-cta {
        margin-left: 0;
      }
    }

    /* Hero */
    .hero {
      padding: 140px 0 80px;
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-content {
      flex: 1;
    }

    .hero h1 {
      font-size: 56px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.02em;
      margin-bottom: 20px;
      color: #fff;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
    }

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

    .btn-primary {
      background: var(--accent-orange);
      color: #fff;
      border: none;
      padding: 14px 32px;
      border-radius: 40px;
      font-weight: 700;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
      transition: box-shadow 0.3s ease, transform 0.2s;
      box-shadow: 0 4px 15px rgba(255, 107, 53, 0.4);
    }

    .btn-primary:hover {
      box-shadow: 0 0 25px rgba(255, 107, 53, 0.7);
      transform: translateY(-2px);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--electric-cyan);
      color: var(--electric-cyan);
      padding: 14px 32px;
      border-radius: 40px;
      font-weight: 600;
      text-decoration: none;
      transition: 0.3s;
    }

    .btn-outline:hover {
      background: rgba(0, 229, 255, 0.1);
      box-shadow: 0 0 12px var(--electric-cyan);
    }

    .hero-visual {
      flex: 1;
      position: relative;
      display: flex;
      justify-content: center;
    }

    .hero-visual img {
      max-width: 100%;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.6);
      border: 1px solid rgba(0,229,255,0.3);
    }

    @media (max-width: 768px) {
      .hero {
        flex-direction: column;
        padding: 120px 0 60px;
        text-align: center;
      }
      .hero h1 {
        font-size: 36px;
      }
      .btn-group {
        justify-content: center;
      }
    }

    /* 板块通用 */
    section {
      padding: 80px 0;
    }

    .section-title {
      font-size: 42px;
      font-weight: 600;
      margin-bottom: 16px;
      color: #fff;
      text-align: center;
    }

    .section-sub {
      color: var(--text-secondary);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 48px;
    }

    /* 亮点网格 */
    .features-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 2fr;
      gap: 24px;
      align-items: start;
    }

    .feature-card {
      background: var(--card-bg);
      backdrop-filter: var(--glass-blur);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }

    .feature-card:hover {
      border-color: var(--electric-cyan);
      box-shadow: 0 12px 40px rgba(0,229,255,0.3);
      transform: translateY(-4px);
    }

    .feature-icon {
      font-size: 40px;
      color: var(--electric-cyan);
      margin-bottom: 16px;
    }

    .feature-card h3 {
      font-size: 24px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .data-highlight {
      display: flex;
      flex-direction: column;
      justify-content: center;
      text-align: center;
    }

    .big-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--electric-cyan);
      line-height: 1.2;
    }

    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 对比区 */
    .comparison-row {
      display: flex;
      gap: 24px;
      background: rgba(15,25,55,0.5);
      border-radius: 24px;
      padding: 24px;
      backdrop-filter: blur(10px);
    }

    .compare-col {
      flex: 1;
      background: rgba(20,30,60,0.7);
      border-radius: 20px;
      padding: 32px;
      border: 1px solid transparent;
      transition: 0.3s;
    }

    .compare-col:first-child {
      border-color: rgba(0,229,255,0.4);
    }
    .compare-col:last-child {
      border-color: rgba(255,107,53,0.4);
    }

    .compare-col h3 {
      font-size: 26px;
      margin-bottom: 20px;
    }

    .feature-list {
      list-style: none;
      margin-bottom: 24px;
    }

    .feature-list li {
      padding: 8px 0;
      display: flex;
      align-items: center;
      gap: 8px;
      color: var(--text-secondary);
    }

    @media (max-width: 768px) {
      .comparison-row {
        flex-direction: column;
      }
    }

    /* 案例瀑布流 */
    .masonry {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .masonry-card {
      background: var(--card-bg);
      backdrop-filter: var(--glass-blur);
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: transform 0.3s;
    }

    .masonry-card:hover {
      transform: translateY(-4px);
    }

    .masonry-card img {
      width: 100%;
      display: block;
      aspect-ratio: 16/9;
      object-fit: cover;
    }

    .card-body {
      padding: 20px;
    }

    .stat-card {
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 32px;
    }

    @media (max-width: 768px) {
      .masonry {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
    }

    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.1);
      padding-bottom: 12px;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      font-size: 18px;
      padding: 16px 0;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
    }

    @media (max-width: 768px) {
      .faq-grid {
        grid-template-columns: 1fr;
      }
    }

    /* CTA 横幅 */
    .cta-banner {
      background: #060B1F;
      text-align: center;
      padding: 80px 20px;
      position: relative;
    }

    .cta-banner h2 {
      font-size: 42px;
      margin-bottom: 16px;
    }

    /* 页脚 */
    .footer {
      background: #080C1A;
      padding: 60px 0 30px;
      color: var(--text-secondary);
    }

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

    .footer-col h4 {
      color: #fff;
      margin-bottom: 16px;
    }

    .footer a {
      color: var(--text-secondary);
      text-decoration: none;
      display: block;
      margin-bottom: 8px;
    }

    .footer a:hover {
      color: var(--electric-cyan);
    }

    .copyright {
      text-align: center;
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid rgba(255,255,255,0.1);
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .section-title {
        font-size: 28px;
      }
    }