/* roulang page: index */
:root {
      --primary-deep: #0A0E17;
      --accent-red: #E63917;
      --warm-gold: #F4A261;
      --bg-light: #FAFAFA;
      --card-white: #FFFFFF;
      --text-body: #3A3D42;
      --text-light: #6B6E75;
      --border-subtle: rgba(10, 14, 23, 0.08);
      --shadow-card: 0 2px 12px rgba(10, 14, 23, 0.06);
      --shadow-elevated: 0 8px 30px rgba(230, 57, 23, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition-smooth: all 0.25s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }

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

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

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

    /* 导航 */
    .nav {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid var(--border-subtle);
      transition: background 0.3s ease;
    }
    .nav.scrolled {
      background: rgba(255, 255, 255, 0.98);
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary-deep);
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
      letter-spacing: -0.5px;
    }
    .logo-icon {
      width: 28px;
      height: 28px;
      background: var(--accent-red);
      border-radius: 6px;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .logo-icon::after {
      content: "";
      width: 10px;
      height: 10px;
      background: white;
      border-radius: 50%;
      position: absolute;
      top: 4px;
      right: 4px;
    }
    .nav-links {
      display: flex;
      gap: 48px;
      list-style: none;
      align-items: center;
    }
    .nav-links a {
      text-decoration: none;
      color: var(--primary-deep);
      font-weight: 500;
      font-size: 15px;
      transition: color 0.2s;
      position: relative;
      padding-bottom: 4px;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-red);
    }
    .nav-links a.active::after {
      content: "";
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-red);
    }
    .btn-primary {
      background: var(--accent-red);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      cursor: pointer;
      transition: var(--transition-smooth);
      text-decoration: none;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: #FF4D2E;
      transform: translateY(-2px);
      box-shadow: 0 10px 20px rgba(230, 57, 23, 0.25);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent-red);
      color: var(--accent-red);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition-smooth);
      text-decoration: none;
    }
    .btn-outline:hover {
      background: var(--accent-red);
      color: white;
      transform: translateY(-2px);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary-deep);
      transition: 0.3s;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--primary-deep);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      z-index: 99;
      transform: translateX(100%);
      transition: transform 0.4s ease;
    }
    .mobile-menu.open {
      transform: translateX(0);
    }
    .mobile-menu a {
      color: white;
      font-size: 24px;
      text-decoration: none;
      font-weight: 600;
    }
    .close-menu {
      position: absolute;
      top: 24px;
      right: 24px;
      background: none;
      border: none;
      color: white;
      font-size: 32px;
      cursor: pointer;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      background: var(--primary-deep);
      position: relative;
      overflow: hidden;
    }
    .hero-content {
      flex: 1;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      text-align: center;
      padding: 40px 24px;
      z-index: 2;
    }
    .hero h1 {
      font-size: 56px;
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.1;
      color: white;
      margin-bottom: 20px;
    }
    .hero h1 span {
      color: var(--accent-red);
    }
    .hero-sub {
      font-size: 18px;
      color: rgba(255,255,255,0.7);
      max-width: 600px;
      margin-bottom: 36px;
    }
    .hero-actions {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
      justify-content: center;
    }
    .hero-visual {
      width: 100%;
      height: 320px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .hero-visual::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: linear-gradient(to bottom, var(--primary-deep) 0%, transparent 40%);
    }

    /* 区块标题 */
    .section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 40px;
      font-weight: 700;
      letter-spacing: -0.01em;
      color: var(--primary-deep);
      margin-bottom: 16px;
    }
    .section-desc {
      color: var(--text-light);
      font-size: 18px;
      max-width: 700px;
      margin-bottom: 48px;
    }

    /* 核心优势 2:1:2 */
    .features-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 2fr;
      gap: 32px;
      align-items: start;
    }
    .feature-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-subtle);
      transition: var(--transition-smooth);
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: 0 20px 30px rgba(0,0,0,0.08);
    }
    .feature-icon {
      width: 48px;
      height: 48px;
      background: rgba(230,57,23,0.08);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--accent-red);
    }
    .feature-card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    /* 科技矩阵 */
    .tech-layout {
      display: grid;
      grid-template-columns: 1fr 1.5fr;
      gap: 60px;
      align-items: center;
    }
    .tech-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .tech-item {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-card);
      display: flex;
      gap: 16px;
    }
    .tech-item img {
      width: 60px;
      height: 60px;
      object-fit: cover;
      border-radius: 8px;
    }

    /* 场景横向滚动 */
    .scenarios-track {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 20px;
      scroll-snap-type: x mandatory;
    }
    .scenario-card {
      min-width: 300px;
      flex: 0 0 auto;
      border-radius: var(--radius-card);
      overflow: hidden;
      position: relative;
      height: 360px;
      background-size: cover;
      background-position: center;
      scroll-snap-align: start;
    }
    .scenario-info {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      padding: 24px;
      background: linear-gradient(transparent, rgba(0,0,0,0.8));
      color: white;
    }

    /* 数据墙 */
    .stats-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .big-numbers {
      display: flex;
      flex-direction: column;
      gap: 40px;
    }
    .stat-item h3 {
      font-size: 48px;
      color: var(--accent-red);
      font-weight: 700;
    }
    .logo-wall {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .logo-wall img {
      width: 100%;
      filter: grayscale(1);
      opacity: 0.7;
      transition: 0.3s;
    }
    .logo-wall img:hover {
      filter: none;
      opacity: 1;
    }

    /* 价格 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .price-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 36px 28px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-subtle);
      text-align: center;
    }
    .price-card.featured {
      background: var(--accent-red);
      color: white;
      border: none;
      box-shadow: var(--shadow-elevated);
      transform: scale(1.03);
    }
    .price-amount {
      font-size: 48px;
      font-weight: 700;
      margin: 16px 0;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-subtle);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-light);
    }

    /* CTA */
    .cta-band {
      background: var(--primary-deep);
      padding: 80px 0;
      text-align: center;
      color: white;
      background-image: url('/assets/images/backpic/back-2.webp');
      background-size: cover;
      background-position: center;
    }

    /* 页脚 */
    .footer {
      background: var(--primary-deep);
      color: rgba(255,255,255,0.8);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: 1fr 1fr; }
      .tech-layout { grid-template-columns: 1fr; }
      .pricing-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero h1 { font-size: 36px; }
      .section { padding: 60px 0; }
      .features-grid, .pricing-grid, .stats-grid, .footer-grid { grid-template-columns: 1fr; }
      .scenario-card { min-width: 260px; }
    }