/* roulang page: index */
:root {
      --deep-green: #0A2E1F;
      --mid-green: #1B5E3F;
      --competition-orange: #F15A24;
      --orange-hover: #D94A1A;
      --warm-bg: #F7F5F0;
      --white: #ffffff;
      --text-dark: #1A1A1A;
      --text-body: #4A4A4A;
      --text-muted: #7A7A7A;
      --border-light: rgba(0,0,0,0.06);
      --card-shadow: 0 4px 24px rgba(0,0,0,0.06);
      --card-shadow-hover: 0 8px 32px rgba(0,0,0,0.12);
      --radius-card: 16px;
      --radius-button: 40px;
      --font-sans: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --transition-smooth: 0.3s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--warm-bg);
      color: var(--text-body);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .nav-bar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: var(--white);
      box-shadow: 0 1px 0 var(--border-light);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--deep-green);
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .logo span {
      font-size: 12px;
      font-weight: 400;
      color: var(--text-muted);
      letter-spacing: 2px;
      border-left: 1px solid #ddd;
      padding-left: 12px;
    }
    .nav-menu {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-body);
      position: relative;
      padding: 8px 0;
    }
    .nav-link:hover,
    .nav-link.active {
      color: var(--competition-orange);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--competition-orange);
      border-radius: 2px;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--deep-green);
      transition: var(--transition-smooth);
    }
    .mobile-overlay {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: var(--deep-green);
      z-index: 999;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 32px;
    }
    .mobile-overlay.active {
      display: flex;
    }
    .mobile-overlay .nav-link {
      color: white;
      font-size: 20px;
    }
    .close-overlay {
      position: absolute;
      top: 24px;
      right: 24px;
      background: none;
      border: none;
      color: white;
      font-size: 32px;
      cursor: pointer;
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0A2E1F 0%, #1B5E3F 100%);
      min-height: 85vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      margin-top: 72px;
    }
    .hero-pattern {
      position: absolute;
      inset: 0;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 100" opacity="0.08"><path d="M0 80 Q 50 20 100 80 T 200 80" stroke="white" fill="none" stroke-width="2"/><circle cx="30" cy="70" r="3" fill="white"/><circle cx="170" cy="40" r="4" fill="white"/></svg>');
      background-size: cover;
      pointer-events: none;
    }
    .hero-content {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 1;
    }
    .hero h1 {
      font-size: 42px;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: white;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      font-weight: 400;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--competition-orange);
      color: white;
      border: none;
      padding: 14px 36px;
      border-radius: 40px;
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: var(--transition-smooth);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--orange-hover);
      box-shadow: 0 6px 20px rgba(241,90,36,0.4);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--deep-green);
      color: var(--competition-orange);
      padding: 12px 34px;
      border-radius: 40px;
      font-weight: 600;
      transition: var(--transition-smooth);
    }
    .btn-outline:hover {
      background: var(--deep-green);
      color: white;
    }
    .hero-image {
      flex: 1;
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      display: block;
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      font-size: 32px;
      font-weight: 700;
      color: var(--text-dark);
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--card-shadow);
      transition: var(--transition-smooth);
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-shadow-hover);
    }
    .icon-circle {
      width: 64px;
      height: 64px;
      background: #E8F5E9;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
    }
    .service-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .data-badge {
      text-align: center;
      background: #EDF2EE;
      border-radius: var(--radius-card);
      padding: 32px 16px;
    }
    .data-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--competition-orange);
    }
    .advantage-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 60px;
    }
    .advantage-row.reverse {
      flex-direction: row-reverse;
    }
    .adv-text {
      flex: 1;
    }
    .adv-text h3 {
      font-size: 24px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .adv-text .orange-line {
      width: 40px;
      height: 2px;
      background: var(--competition-orange);
      margin-top: 20px;
    }
    .adv-img {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--card-shadow);
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--card-shadow);
    }
    .case-img {
      height: 200px;
      object-fit: cover;
    }
    .case-info {
      padding: 24px;
    }
    .faq-item {
      border-bottom: 1px solid #eee;
    }
    .faq-question {
      background: #F9F9F9;
      padding: 20px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
    }
    .faq-answer {
      padding: 0 20px 20px;
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .cta-section {
      background: var(--deep-green);
      text-align: center;
      padding: 80px 0;
    }
    .footer {
      background: #1A1A1A;
      color: #AAAAAA;
      padding: 60px 0 30px;
    }
    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2,1fr); }
      .hero-content { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .grid-4, .grid-3 { grid-template-columns: 1fr; }
      .advantage-row, .advantage-row.reverse { flex-direction: column; }
      .hero h1 { font-size: 30px; }
      section { padding: 60px 0; }
    }