/* roulang page: index */
:root {
      --primary: #E8451E;
      --primary-glow: rgba(232, 69, 30, 0.6);
      --secondary: #0F0F0F;
      --accent: #00D2FF;
      --accent-glow: rgba(0, 210, 255, 0.5);
      --gray: #A8A9AD;
      --gray-light: #F5F5F7;
      --white: #FFFFFF;
      --card-shadow: 0 8px 28px rgba(0,0,0,0.08);
      --card-hover-shadow: 0 18px 40px rgba(0,0,0,0.15);
      --radius-lg: 20px;
      --radius-md: 14px;
      --radius-sm: 10px;
      --font-sans: 'Noto Sans SC', 'Inter', system-ui, -apple-system, sans-serif;
      --transition: 0.25s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--white);
      color: #1A1A1A;
      line-height: 1.6;
      overflow-x: hidden;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
      width: 100%;
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      padding: 1rem 0;
      transition: background 0.3s, backdrop-filter 0.3s, box-shadow 0.3s;
      background: transparent;
      backdrop-filter: blur(0px);
    }
    .navbar.scrolled {
      background: rgba(15,15,15,0.88);
      backdrop-filter: blur(14px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.4);
      border-bottom: 1px solid rgba(168,169,173,0.2);
    }
    .navbar .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 900;
      color: var(--white);
      text-decoration: none;
      letter-spacing: -0.5px;
      background: linear-gradient(135deg, var(--primary) 0%, #FF6B42 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      transition: opacity 0.2s;
    }
    .logo span {
      font-weight: 700;
      background: none;
      -webkit-text-fill-color: var(--white);
      margin-left: 4px;
      font-size: 1.2rem;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2rem;
      list-style: none;
    }
    .nav-menu a {
      color: rgba(255,255,255,0.85);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      letter-spacing: 0.3px;
    }
    .nav-menu a:hover {
      color: var(--accent);
    }
    .nav-cta {
      background: var(--primary);
      color: white !important;
      padding: 0.6rem 1.5rem;
      border-radius: 2rem;
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(232,69,30,0.4);
      transition: all var(--transition);
      white-space: nowrap;
    }
    .nav-cta:hover {
      background: #ff5722;
      box-shadow: 0 6px 20px var(--primary-glow);
      transform: translateY(-1px);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
      cursor: pointer;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      background: radial-gradient(circle at 30% 40%, #1a1a1a, var(--secondary) 90%);
      position: relative;
      overflow: hidden;
      text-align: center;
      padding-top: 5rem;
    }
    .hero-canvas {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
      opacity: 0.9;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 900px;
      margin: 0 auto;
    }
    .hero h1 {
      font-size: clamp(2.8rem, 7vw, 5.2rem);
      font-weight: 900;
      line-height: 1.15;
      color: white;
      margin-bottom: 1.5rem;
      letter-spacing: -0.02em;
      text-shadow: 0 4px 20px rgba(0,0,0,0.6);
      animation: fadeUp 0.9s ease;
    }
    .hero .subtitle {
      font-size: 1.3rem;
      color: var(--gray);
      margin-bottom: 2.5rem;
      max-width: 650px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      justify-content: center;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-block;
      padding: 0.85rem 2.2rem;
      border-radius: 3rem;
      font-weight: 600;
      text-decoration: none;
      transition: all var(--transition);
      border: 2px solid transparent;
      cursor: pointer;
      font-size: 1rem;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
      box-shadow: 0 6px 18px rgba(232,69,30,0.45);
    }
    .btn-primary:hover {
      background: #ff5722;
      box-shadow: 0 8px 24px var(--primary-glow);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border-color: var(--accent);
      color: var(--accent);
    }
    .btn-outline:hover {
      background: rgba(0,210,255,0.1);
      border-color: white;
      color: white;
    }
    .hero-stats {
      display: flex;
      justify-content: center;
      gap: 3rem;
      margin-top: 4rem;
      flex-wrap: wrap;
    }
    .stat-item {
      color: white;
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--accent);
      font-family: 'Inter', sans-serif;
      line-height: 1.2;
    }
    .stat-label {
      color: var(--gray);
      font-size: 0.9rem;
      letter-spacing: 0.5px;
    }
    /* 板块通用 */
    section {
      padding: 5rem 0;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      margin-bottom: 2.5rem;
      letter-spacing: -0.01em;
      color: #111;
    }
    .section-title.center {
      text-align: center;
    }
    /* 核心优势不对称网格 */
    .advantage-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 2rem;
    }
    .adv-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 2.2rem;
      box-shadow: var(--card-shadow);
      transition: all var(--transition);
      border: 1px solid rgba(0,0,0,0.03);
    }
    .adv-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--card-hover-shadow), 0 0 0 2px var(--accent-glow);
    }
    .adv-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 1.2rem;
    }
    .adv-card h3 {
      font-size: 1.6rem;
      margin-bottom: 0.8rem;
    }
    .adv-card p {
      color: #4a4a4a;
    }
    /* 产品横向滚动 */
    .products-wrapper {
      overflow-x: auto;
      display: flex;
      gap: 1.8rem;
      padding-bottom: 1rem;
      scroll-snap-type: x mandatory;
      -webkit-overflow-scrolling: touch;
      scrollbar-width: thin;
    }
    .product-card {
      flex: 0 0 320px;
      scroll-snap-align: start;
      background: white;
      border-radius: var(--radius-lg);
      box-shadow: var(--card-shadow);
      transition: all var(--transition);
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }
    .product-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--card-hover-shadow), 0 0 0 2px var(--accent-glow);
    }
    .product-img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .product-tag {
      background: var(--primary);
      color: white;
      padding: 0.2rem 1rem;
      border-radius: 2rem;
      font-size: 0.75rem;
      font-weight: 600;
      align-self: flex-start;
      margin: 1rem 1.2rem 0;
    }
    .product-card h3 {
      padding: 0 1.2rem;
      font-size: 1.35rem;
      margin: 0.5rem 0 0.3rem;
    }
    .product-card p {
      padding: 0 1.2rem;
      color: #555;
      font-size: 0.9rem;
      flex: 1;
    }
    .product-arrow {
      padding: 1rem 1.2rem;
      color: var(--accent);
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 0.3rem;
      transition: gap 0.2s;
      cursor: pointer;
    }
    .product-arrow:hover {
      gap: 0.6rem;
    }
    /* 数据区 */
    .data-section {
      background: var(--secondary);
      background-image: url('/assets/images/backpic/back-2.webp');
      background-size: cover;
      background-blend-mode: overlay;
      color: white;
    }
    .data-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 2rem;
    }
    .data-item .big-number {
      font-size: 4rem;
      font-weight: 800;
      color: var(--accent);
      font-family: 'Inter', sans-serif;
    }
    /* 案例区 */
    .case-row {
      display: flex;
      gap: 2.5rem;
      align-items: center;
      margin-bottom: 3rem;
    }
    .case-row.reverse {
      flex-direction: row-reverse;
    }
    .case-img {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: 0 8px 24px rgba(0,0,0,0.1);
    }
    .case-text {
      flex: 1;
    }
    .logo-wall {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 2.5rem;
      opacity: 0.7;
      margin: 2rem 0;
    }
    /* 时间轴 */
    .timeline {
      position: relative;
      padding-left: 2.5rem;
    }
    .timeline::before {
      content: '';
      position: absolute;
      left: 1rem;
      top: 0;
      bottom: 0;
      width: 3px;
      background: linear-gradient(to bottom, var(--accent), var(--primary));
    }
    .timeline-step {
      margin-bottom: 2.5rem;
      position: relative;
    }
    .timeline-icon {
      position: absolute;
      left: -2.5rem;
      background: var(--primary);
      color: white;
      width: 2.2rem;
      height: 2.2rem;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1.5rem;
    }
    .faq-item {
      background: white;
      border-radius: var(--radius-md);
      padding: 1.5rem;
      box-shadow: 0 4px 14px rgba(0,0,0,0.04);
      cursor: pointer;
    }
    .faq-question {
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: #444;
    }
    /* CTA 横幅 */
    .cta-band {
      background: var(--secondary);
      background-image: url('/assets/images/backpic/back-3.webp');
      background-blend-mode: soft-light;
      text-align: center;
      padding: 4rem 0;
      color: white;
    }
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.2fr;
      gap: 2rem;
    }
    footer {
      background: #0A0A0A;
      color: #ccc;
      padding: 3rem 0 1.5rem;
    }
    @keyframes fadeUp {
      0% { opacity: 0; transform: translateY(25px); }
      100% { opacity: 1; transform: translateY(0); }
    }
    @media (max-width: 1024px) {
      .advantage-grid { grid-template-columns: 1fr 1fr; }
      .faq-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: block; }
      .hero h1 { font-size: 2.6rem; }
      .case-row, .case-row.reverse { flex-direction: column; }
      .advantage-grid { grid-template-columns: 1fr; }
    }