/* roulang page: index */
:root {
      --primary: #1A56DB;
      --primary-dark: #1647b0;
      --accent: #F97316;
      --accent-dark: #EA580C;
      --deep: #111827;
      --gray-bg: #F8FAFC;
      --card-white: #FFFFFF;
      --success: #10B981;
      --border-light: #E2E8F0;
      --text-soft: #4B5563;
      --text-muted: #6B7280;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-hover: 0 10px 25px rgba(0,0,0,0.08);
      --transition: 0.25s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Inter", system-ui, sans-serif;
      --section-gap: 5rem;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--gray-bg);
      color: var(--deep);
      line-height: 1.7;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, .button {
      cursor: pointer;
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    /* 导航栏 */
    #header {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      position: sticky;
      top: 0;
      z-index: 40;
      padding: 0.75rem 0;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: nowrap;
    }

    .logo-brand {
      font-weight: 800;
      font-size: 1.75rem;
      color: var(--primary);
      letter-spacing: -0.3px;
      white-space: nowrap;
      display: flex;
      align-items: center;
      gap: 0.25rem;
    }
    .logo-brand i {
      color: var(--accent);
      font-size: 2rem;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 1.75rem;
      list-style: none;
      flex-wrap: wrap;
    }

    .nav-links a {
      font-weight: 600;
      font-size: 0.95rem;
      color: var(--deep);
      padding: 0.4rem 0;
      border-bottom: 3px solid transparent;
      transition: color var(--transition), border-color var(--transition);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--deep);
    }

    /* Hero */
    #hero {
      background: linear-gradient(135deg, #1A56DB 0%, #2563EB 100%);
      position: relative;
      overflow: hidden;
      padding: 5rem 0 4rem;
      color: white;
    }
    #hero::before {
      content: "";
      position: absolute;
      inset: 0;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 800 600"><path d="M0 400 Q200 200 400 400 T800 350" stroke="rgba(255,255,255,0.08)" stroke-width="2" fill="none"/><circle cx="150" cy="80" r="40" stroke="rgba(255,255,255,0.06)" stroke-width="2" fill="none"/><circle cx="650" cy="450" r="70" stroke="rgba(255,255,255,0.05)" stroke-width="2" fill="none"/></svg>');
      background-size: cover;
      pointer-events: none;
      opacity: 0.5;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 1 1 50%;
    }
    .hero-text h1 {
      font-size: clamp(2.5rem, 5vw, 3.5rem);
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 1.25rem;
    }
    .hero-text h3 {
      font-size: 1.3rem;
      font-weight: 500;
      opacity: 0.9;
      margin-bottom: 2rem;
    }
    .btn-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
      align-items: center;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      font-weight: 700;
      padding: 0.8rem 2.2rem;
      border-radius: var(--radius-btn);
      display: inline-flex;
      align-items: center;
      gap: 0.4rem;
      transition: background var(--transition), transform 0.2s;
      border: none;
      font-size: 1rem;
    }
    .btn-primary:hover {
      background: var(--accent-dark);
      transform: scale(1.03);
      color: white;
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid white;
      color: white;
      font-weight: 600;
      padding: 0.7rem 2rem;
      border-radius: var(--radius-btn);
      transition: background var(--transition), transform 0.2s;
    }
    .btn-secondary:hover {
      background: rgba(255,255,255,0.15);
      transform: scale(1.03);
    }
    .hero-image {
      flex: 1 1 45%;
      background: rgba(255,255,255,0.1);
      border-radius: 20px;
      overflow: hidden;
      box-shadow: 0 20px 35px rgba(0,0,0,0.2);
    }
    .hero-image img {
      object-fit: cover;
      width: 100%;
      height: auto;
      aspect-ratio: 4/3;
      border-radius: 20px;
    }

    /* sections */
    section {
      padding: var(--section-gap) 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 2.5rem;
    }
    .section-title h2 {
      font-size: 2.3rem;
      font-weight: 700;
      color: var(--deep);
      margin-bottom: 0.75rem;
    }
    .section-title p {
      color: var(--text-soft);
      font-size: 1.1rem;
      max-width: 700px;
      margin: 0 auto;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.8rem;
    }

    .card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 2rem 1.8rem;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
    }
    .card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 50px;
      height: 50px;
      border-radius: 50%;
      background: var(--primary);
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      margin-bottom: 1.2rem;
      transition: background var(--transition);
    }
    .card:hover .icon-circle {
      background: var(--accent);
    }
    .card h4 {
      font-weight: 700;
      font-size: 1.25rem;
      margin-bottom: 0.5rem;
    }
    .card p {
      color: var(--text-muted);
      font-size: 0.95rem;
      line-height: 1.6;
    }

    .solutions-flex {
      display: flex;
      align-items: center;
      gap: 3rem;
      flex-wrap: wrap;
    }
    .solutions-text {
      flex: 1 1 45%;
    }
    .solutions-img {
      flex: 1 1 45%;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .solutions-img img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .check-list {
      list-style: none;
      margin: 1.5rem 0;
    }
    .check-list li {
      margin-bottom: 0.7rem;
      display: flex;
      align-items: center;
      gap: 0.6rem;
      color: var(--deep);
    }
    .check-list i {
      color: var(--success);
    }

    .process-steps {
      display: flex;
      justify-content: space-between;
      text-align: center;
      position: relative;
    }
    .step {
      flex: 1;
      padding: 0 1rem;
    }
    .step-number {
      background: #EFF6FF;
      color: var(--primary);
      width: 48px;
      height: 48px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1.5rem;
      margin: 0 auto 0.8rem;
    }
    .testimonials-block {
      background: #EFF6FF;
      border-radius: 24px;
      padding: 3rem 2rem;
      display: flex;
      gap: 2.5rem;
      flex-wrap: wrap;
    }
    .stats {
      flex: 0 0 260px;
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--success);
    }
    .quote-card {
      background: white;
      border-left: 5px solid var(--accent);
      padding: 1.5rem;
      border-radius: 12px;
      box-shadow: var(--shadow-sm);
      flex: 1;
    }

    .accordion-item {
      background: white;
      border-radius: 10px;
      margin-bottom: 12px;
      box-shadow: 0 1px 6px rgba(0,0,0,0.04);
    }
    .accordion-title {
      font-weight: 700;
      padding: 1.1rem 1.5rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .cta-final {
      background: #1A56DB;
      color: white;
      text-align: center;
      padding: 4rem 2rem;
      border-radius: 28px;
      margin: 2rem 0 3rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 2rem;
    }
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .hero-grid { flex-direction: column; }
      .grid-3 { grid-template-columns: 1fr; }
      .solutions-flex { flex-direction: column; }
      .process-steps { flex-direction: column; gap: 1.5rem; }
      .testimonials-block { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; }
      #hero { padding: 3rem 0; }
    }
    .mobile-menu {
      display: none;
      flex-direction: column;
      background: white;
      padding: 2rem;
      position: absolute;
      top: 70px;
      left: 0;
      right: 0;
      box-shadow: 0 20px 30px rgba(0,0,0,0.1);
    }
    .mobile-menu a {
      padding: 0.8rem;
      font-weight: 600;
    }