/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary-orange: #FF4D00;
      --primary-gradient: linear-gradient(135deg, #FF4D00 0%, #FF7A33 100%);
      --deep-black: #1A1A1A;
      --dark-bg: #2D2D2D;
      --compete-white: #F9F9FB;
      --track-cyan: #00E5A0;
      --text-dark: #1A1A1A;
      --text-muted: #4A4A4A;
      --body-bg: #FFFFFF;
      --card-shadow: 0 4px 20px rgba(0,0,0,0.04);
      --card-hover-shadow: 0 12px 32px rgba(255,77,0,0.12);
      --border-light: rgba(0,0,0,0.05);
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-search: 24px;
      --font-cn: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-en: "Inter", "SF Pro Display", sans-serif;
    }

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

    body {
      font-family: var(--font-cn);
      background-color: var(--body-bg);
      color: var(--text-dark);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    h1, h2, h3, h4 {
      font-family: var(--font-cn);
      font-weight: 700;
      line-height: 1.2;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }

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

    button, .button {
      cursor: pointer;
      font-family: var(--font-cn);
      border: none;
      background: transparent;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }

    input {
      font-family: var(--font-cn);
    }

    /* 容器与栅格微调 */
    .custom-container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    section {
      padding: 80px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }

    /* ----- 导航栏 SaaS 命令栏风格 ----- */
    .top-nav {
      position: sticky;
      top: 0;
      z-index: 999;
      height: 72px;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid var(--border-light);
      display: flex;
      align-items: center;
      transition: background 0.3s;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    .logo-area {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo-text {
      font-weight: 700;
      font-size: 1.4rem;
      background: var(--primary-gradient);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: -0.3px;
    }

    .logo-sub {
      font-size: 0.7rem;
      color: var(--text-muted);
      margin-left: 4px;
      font-weight: 500;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .nav-links a {
      font-weight: 500;
      color: var(--text-dark);
      position: relative;
      padding: 4px 0;
      font-size: 0.95rem;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-orange);
      transition: width 0.3s ease;
    }

    .nav-links a:hover {
      color: var(--primary-orange);
    }

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

    .nav-right {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .search-box {
      background: #f2f2f5;
      border-radius: var(--radius-search);
      padding: 6px 16px;
      display: flex;
      align-items: center;
      gap: 6px;
      border: 1px solid transparent;
      transition: 0.2s;
    }

    .search-box i {
      color: #8a8a8e;
      font-size: 0.9rem;
    }

    .search-box input {
      border: none;
      background: transparent;
      outline: none;
      font-size: 0.9rem;
      width: 130px;
    }

    .icon-bell {
      color: #4a4a4a;
      font-size: 1.2rem;
      transition: color 0.2s;
    }

    .icon-bell:hover {
      color: var(--primary-orange);
    }

    .btn-primary-small {
      background: var(--primary-gradient);
      color: #fff;
      border-radius: var(--radius-btn);
      padding: 10px 24px;
      font-weight: 600;
      font-size: 0.9rem;
      box-shadow: 0 4px 14px rgba(255,77,0,0.25);
      letter-spacing: 0.5px;
    }

    .btn-primary-small:hover {
      box-shadow: 0 8px 22px rgba(255,77,0,0.45);
      transform: translateY(-2px);
    }

    .mobile-menu-toggle {
      display: none;
      font-size: 1.8rem;
      background: none;
      color: var(--text-dark);
    }

    @media (max-width: 768px) {
      .nav-links, .nav-right .search-box, .nav-right .icon-bell {
        display: none;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .nav-right .btn-primary-small {
        display: none;
      }
    }

    /* ----- Hero 全屏首屏 ----- */
    .hero-section {
      height: 100vh;
      min-height: 600px;
      background: linear-gradient(135deg, rgba(26,26,26,0.78) 0%, rgba(45,45,45,0.8) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      display: flex;
      align-items: center;
      position: relative;
      color: white;
    }

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

    .hero-left {
      flex: 1 1 50%;
    }

    .hero-left h1 {
      font-size: 3.8rem;
      font-weight: 700;
      line-height: 1.1;
      letter-spacing: -1px;
      color: white;
      margin-bottom: 1.2rem;
    }

    .hero-sub {
      font-size: 1.2rem;
      color: var(--track-cyan);
      letter-spacing: 2px;
      font-weight: 500;
      margin-bottom: 2rem;
      text-transform: uppercase;
    }

    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }

    .btn-main {
      background: var(--primary-gradient);
      color: #fff;
      border-radius: var(--radius-btn);
      padding: 14px 36px;
      font-weight: 600;
      letter-spacing: 0.5px;
      box-shadow: 0 8px 24px rgba(255,77,0,0.3);
      font-size: 1rem;
    }

    .btn-main:hover {
      box-shadow: 0 12px 32px rgba(255,77,0,0.45);
      transform: translateY(-2px);
    }

    .btn-outline {
      border: 2px solid white;
      color: white;
      background: transparent;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
    }

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

    .hero-right {
      flex: 1 1 45%;
      display: flex;
      justify-content: center;
      align-items: center;
      position: relative;
    }

    .hero-ball-container {
      width: 320px;
      height: 320px;
      background: radial-gradient(circle at 30% 30%, rgba(255,255,255,0.15), rgba(0,0,0,0.3));
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      backdrop-filter: blur(8px);
      position: relative;
    }

    .hero-ball-container img {
      width: 75%;
      filter: drop-shadow(0 10px 15px rgba(0,0,0,0.4));
    }

    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      left: 50%;
      transform: translateX(-50%);
      display: flex;
      flex-direction: column;
      align-items: center;
      color: rgba(255,255,255,0.7);
      animation: pulse 2s infinite;
    }

    @keyframes pulse {
      0% { opacity: 0.6; transform: translateX(-50%) translateY(0); }
      50% { opacity: 1; transform: translateX(-50%) translateY(5px); }
      100% { opacity: 0.6; transform: translateX(-50%) translateY(0); }
    }

    @media (max-width: 768px) {
      .hero-section {
        height: auto;
        padding: 100px 0 80px;
      }
      .hero-grid {
        flex-direction: column;
        text-align: center;
        gap: 40px;
      }
      .hero-left h1 {
        font-size: 2.4rem;
      }
      .hero-buttons {
        justify-content: center;
      }
    }

    /* ----- 核心优势 非对称布局 ----- */
    .why-us {
      background: var(--compete-white);
    }

    .asym-grid {
      display: flex;
      gap: 24px;
    }

    .left-big-card {
      flex: 5;
      background: white;
      border-radius: 20px;
      padding: 2rem;
      box-shadow: var(--card-shadow);
      border-left: 4px solid var(--primary-orange);
    }

    .right-stack {
      flex: 7;
      display: flex;
      flex-direction: column;
      gap: 24px;
    }

    .small-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 1.8rem;
      box-shadow: var(--card-shadow);
      transition: all 0.3s ease;
      border-left: 4px solid transparent;
    }

    .small-card:hover {
      border-left-color: var(--track-cyan);
      box-shadow: var(--card-hover-shadow);
    }

    .data-badge-inline {
      background: var(--track-cyan);
      color: #1A1A1A;
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.9rem;
      display: inline-block;
      margin-top: 10px;
    }

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

    /* ----- 数据徽章区 ----- */
    .data-badges {
      background: var(--primary-gradient);
      color: white;
    }

    .badge-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
    }

    .badge-item .number {
      font-family: var(--font-en);
      font-weight: 800;
      font-size: 3rem;
      color: white;
    }

    .badge-item .desc {
      font-size: 1rem;
      opacity: 0.9;
    }

    /* ----- 服务网格 2x3 ----- */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .service-card {
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--card-shadow);
      overflow: hidden;
      transition: all 0.3s ease;
    }

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

    .service-img {
      height: 180px;
      overflow: hidden;
    }

    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s;
    }

    .service-card:hover .service-img img {
      transform: scale(1.03);
    }

    .service-content {
      padding: 1.5rem;
    }

    @media (max-width: 1023px) {
      .services-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 640px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ 两栏 */
    .faq-grid {
      display: flex;
      gap: 3rem;
    }

    .faq-left {
      flex: 1;
    }

    .faq-right {
      flex: 1.5;
    }

    .accordion-item {
      border-bottom: 1px solid #e0e0e0;
      padding: 1rem 0;
    }

    .accordion-title {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-muted);
    }

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

    /* Footer CTA */
    .footer-cta {
      background: var(--primary-gradient);
      color: white;
      text-align: center;
      padding: 70px 0;
    }

    .footer-main {
      background: var(--deep-black);
      color: #ccc;
      padding: 3rem 0 1.5rem;
    }

    .footer-grid {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 2rem;
    }

    .copyright {
      text-align: center;
      margin-top: 2rem;
      color: #888;
    }