/* roulang page: index */
:root {
      --deep-black: #1A1A1A;
      --sport-red: #D32F2F;
      --sport-red-hover: #B71C1C;
      --track-gray: #4A4A4A;
      --bg-white: #FFFFFF;
      --bg-light: #F5F5F5;
      --border-light: #E0E0E0;
      --text-muted: #888888;
      --container-max: 1280px;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08);
      --transition-smooth: 0.25s ease-out;
      --transition-fast: 0.2s ease;
      --font-h1: 56px;
      --font-h2: 40px;
      --font-h3: 24px;
      --font-h4: 18px;
      --font-body: 16px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Inter', 'Noto Sans SC', sans-serif;
      background: var(--bg-white);
      color: var(--track-gray);
      line-height: 1.6;
      font-size: var(--font-body);
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-fast);
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: all var(--transition-smooth);
      font-weight: 600;
      border-radius: var(--radius-btn);
    }
    h1, h2, h3, h4 {
      color: var(--deep-black);
    }
    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      background: var(--bg-white);
      z-index: 50;
      border-bottom: 1px solid #F0F0F0;
    }
    .nav-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--deep-black);
      letter-spacing: -0.5px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 16px;
      color: var(--deep-black);
      position: relative;
      padding-bottom: 4px;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--sport-red);
      transition: width var(--transition-fast);
    }
    .nav-links a:hover {
      color: var(--sport-red);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--sport-red);
      color: white;
      padding: 12px 28px;
      font-size: 16px;
      border-radius: var(--radius-btn);
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: var(--sport-red-hover);
    }
    .btn-outline {
      border: 1.5px solid var(--deep-black);
      color: var(--deep-black);
      background: transparent;
      padding: 12px 28px;
      font-size: 16px;
      border-radius: var(--radius-btn);
      white-space: nowrap;
    }
    .btn-outline:hover {
      background: var(--deep-black);
      color: white;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--deep-black);
      transition: 0.2s;
    }
    /* 移动端导航抽屉 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: var(--bg-white);
      border-bottom: 1px solid #F0F0F0;
      padding: 24px;
      flex-direction: column;
      gap: 20px;
      z-index: 40;
      box-shadow: 0 10px 20px rgba(0,0,0,0.03);
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
      color: var(--deep-black);
    }
    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      gap: 60px;
      padding: 80px 0 80px;
    }
    .hero-content {
      flex: 1 1 50%;
    }
    .hero-title {
      font-size: var(--font-h1);
      font-weight: 700;
      line-height: 1.1;
      letter-spacing: -0.02em;
      color: var(--deep-black);
      margin-bottom: 20px;
      opacity: 0;
      transform: translateY(20px);
      animation: fadeUp 0.4s forwards 0.1s;
    }
    .hero-sub {
      font-size: 20px;
      color: var(--track-gray);
      margin-bottom: 24px;
      opacity: 0;
      transform: translateY(20px);
      animation: fadeUp 0.4s forwards 0.2s;
    }
    .hero-stats {
      display: flex;
      gap: 32px;
      margin-bottom: 32px;
      opacity: 0;
      transform: translateY(20px);
      animation: fadeUp 0.4s forwards 0.3s;
    }
    .stat-item h3 {
      font-size: 32px;
      font-weight: 700;
      color: var(--sport-red);
    }
    .stat-item span {
      font-size: 14px;
      color: var(--text-muted);
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      opacity: 0;
      transform: translateY(20px);
      animation: fadeUp 0.4s forwards 0.4s;
    }
    .hero-image {
      flex: 1 1 50%;
      border-radius: var(--radius-card);
      overflow: hidden;
      background: #eee;
      position: relative;
      opacity: 0;
      animation: fadeUp 0.6s forwards 0.2s;
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      filter: grayscale(0.3) contrast(1.05);
    }
    @keyframes fadeUp {
      to { opacity: 1; transform: translateY(0); }
    }
    /* 板块通用 */
    .section {
      padding: 100px 0;
    }
    .section-light {
      background: var(--bg-light);
    }
    .section-title {
      font-size: var(--font-h2);
      font-weight: 600;
      margin-bottom: 16px;
    }
    .section-desc {
      color: var(--track-gray);
      max-width: 700px;
      margin-bottom: 48px;
      font-size: 18px;
    }
    /* 核心优势区 - 不对称网格 */
    .advantage-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr;
      gap: 32px;
      align-items: center;
    }
    .advantage-left img {
      width: 100%;
      border-radius: var(--radius-card);
      height: 380px;
      object-fit: cover;
      filter: grayscale(0.2);
    }
    .advantage-right {
      display: flex;
      flex-direction: column;
      gap: 28px;
    }
    .adv-item {
      display: flex;
      gap: 16px;
      align-items: flex-start;
    }
    .adv-icon {
      font-size: 28px;
      color: var(--sport-red);
    }
    .adv-text h4 {
      font-size: var(--font-h4);
      margin-bottom: 4px;
    }
    /* 功能分组 图文交替 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-text {
      flex: 1;
    }
    .service-text h3 {
      font-size: 28px;
      margin-bottom: 16px;
    }
    .service-list {
      list-style: none;
      margin-top: 16px;
    }
    .service-list li {
      margin-bottom: 10px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .service-list li::before {
      content: "●";
      color: var(--sport-red);
      font-size: 14px;
    }
    .service-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
    }
    .service-img img {
      width: 100%;
      height: 300px;
      object-fit: cover;
      filter: grayscale(0.25);
    }
    /* 场景卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .scene-card {
      background: var(--bg-white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      overflow: hidden;
      transition: all var(--transition-smooth);
    }
    .scene-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .scene-card img {
      width: 100%;
      height: 220px;
      object-fit: cover;
      filter: grayscale(0.2);
    }
    .scene-card-content {
      padding: 20px;
    }
    /* 案例卡片数据驱动 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .case-card {
      background: #FAFAFA;
      border-radius: var(--radius-card);
      padding: 24px;
    }
    .case-logo {
      height: 32px;
      width: 80px;
      background: #ddd;
      margin-bottom: 16px;
      border-radius: 4px;
      filter: grayscale(1);
    }
    .case-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--sport-red);
    }
    /* 信任墙 */
    .partner-wall {
      display: flex;
      flex-wrap: wrap;
      gap: 40px;
      align-items: center;
      justify-content: center;
      opacity: 0.7;
      margin: 32px 0;
    }
    .partner-item {
      height: 28px;
      width: 100px;
      background: #ccc;
      border-radius: 6px;
      filter: grayscale(1);
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      background: white;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 18px 0;
      font-weight: 600;
      color: var(--deep-black);
      cursor: pointer;
      font-size: 18px;
    }
    .faq-icon {
      font-size: 24px;
      color: var(--sport-red);
      transition: transform 0.3s ease;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      color: var(--track-gray);
    }
    .faq-item.active .faq-answer {
      max-height: 150px;
      padding-bottom: 16px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* CTA */
    .cta-band {
      background: var(--deep-black);
      padding: 80px 0;
      text-align: center;
      position: relative;
      overflow: hidden;
    }
    .cta-band::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 200%;
      height: 100%;
      background: repeating-linear-gradient(45deg, rgba(255,255,255,0.02) 0px, rgba(255,255,255,0.02) 2px, transparent 2px, transparent 8px);
      animation: moveLines 20s linear infinite;
    }
    @keyframes moveLines {
      0% { transform: translateX(0); }
      100% { transform: translateX(-50%); }
    }
    .cta-content {
      position: relative;
      z-index: 2;
    }
    .cta-content h2 {
      color: white;
    }
    .cta-content p {
      color: #aaa;
      margin: 16px 0 28px;
    }
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      padding: 60px 0 40px;
    }
    .footer-brand p {
      margin-top: 12px;
      color: var(--text-muted);
    }
    .footer-links h4 {
      margin-bottom: 16px;
    }
    .footer-links a {
      display: block;
      margin-bottom: 8px;
      color: var(--track-gray);
    }
    .copyright {
      background: var(--deep-black);
      color: var(--text-muted);
      text-align: center;
      padding: 20px 0;
      font-size: 14px;
    }
    @media (max-width: 1024px) {
      .hero { flex-direction: column; }
      .cards-grid, .case-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu.active { display: flex; }
      .hero { padding: 40px 0; }
      .hero-title { font-size: 36px; }
      .section { padding: 70px 0; }
      .advantage-grid { grid-template-columns: 1fr; }
      .service-row, .service-row.reverse { flex-direction: column; }
      .cards-grid, .case-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-stats { flex-wrap: wrap; }
      .btn-primary, .btn-outline { width: 100%; justify-content: center; }
    }