/* roulang page: index */
:root {
      --primary-dark: #2B3A2B;
      --primary-deeper: #1E2A1E;
      --secondary-warm: #F7F4EF;
      --accent-orange: #E85D04;
      --accent-hover: #D14D00;
      --text-main: #1A1A1A;
      --text-secondary: #5C5C5C;
      --text-muted: #A8A8A8;
      --border-light: #E0DDD6;
      --white: #FFFFFF;
      --data-green: #1B7E4B;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "Inter", "SF Pro Text", sans-serif;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-large: 16px;
      --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.02);
      --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.08);
      --transition-smooth: 0.25s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--secondary-warm);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
      height: 72px;
      display: flex;
      align-items: center;
      transition: box-shadow 0.2s ease;
    }

    .header.shadow {
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
    }

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

    .logo {
      font-weight: 700;
      font-size: 22px;
      color: var(--primary-dark);
      text-decoration: none;
      letter-spacing: 1px;
      white-space: nowrap;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-links a {
      text-decoration: none;
      color: var(--text-secondary);
      font-weight: 500;
      transition: color 0.2s;
      font-size: 16px;
    }

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

    .btn-primary {
      background: var(--accent-orange);
      color: var(--white);
      padding: 12px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: background 0.2s;
      border: none;
      display: inline-block;
      cursor: pointer;
    }

    .btn-primary:hover {
      background: var(--accent-hover);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary-dark);
      color: var(--primary-dark);
      padding: 12px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: all 0.2s;
      display: inline-block;
    }

    .btn-outline:hover {
      background: var(--primary-dark);
      color: var(--white);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary-dark);
      transition: 0.2s;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--secondary-warm);
      z-index: 60;
      flex-direction: column;
      padding: 32px;
      gap: 28px;
    }

    .mobile-menu.active {
      display: flex;
    }

    .mobile-menu .close-btn {
      align-self: flex-end;
      font-size: 32px;
      background: none;
      border: none;
      color: var(--primary-dark);
      cursor: pointer;
    }

    .mobile-menu a {
      font-size: 18px;
      color: var(--text-main);
      text-decoration: none;
      font-weight: 500;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }

      .hamburger {
        display: flex;
      }

      .header {
        height: 60px;
      }

      .logo {
        font-size: 20px;
      }
    }

    /* Hero */
    .hero {
      background: var(--secondary-warm);
      padding: 80px 0;
      position: relative;
      overflow: hidden;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }

    .hero-text {
      flex: 1 1 55%;
    }

    .hero-text h1 {
      font-size: 52px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-main);
      margin-bottom: 24px;
    }

    .hero-text .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      max-width: 480px;
      margin-bottom: 40px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-image {
      flex: 1 1 45%;
      position: relative;
    }

    .hero-image img {
      width: 100%;
      height: auto;
      border-radius: 20px;
      box-shadow: var(--shadow-card);
      transition: transform 0.4s ease;
    }

    .hero-image:hover img {
      transform: scale(1.02);
    }

    .bg-arc {
      position: absolute;
      right: -10%;
      bottom: -10%;
      width: 600px;
      height: 600px;
      background: radial-gradient(circle at 30% 40%, rgba(43, 58, 43, 0.06) 0%, transparent 70%);
      border-radius: 50%;
      z-index: 0;
    }

    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
      }

      .hero-text h1 {
        font-size: 40px;
      }
    }

    @media (max-width: 768px) {
      .hero-text h1 {
        font-size: 34px;
      }
      .hero-text .subtitle {
        font-size: 16px;
      }
    }

    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 70px 0;
      }
    }

    .section-title {
      font-size: 34px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
      text-align: left;
    }

    .section-sub {
      color: var(--text-secondary);
      margin-bottom: 48px;
      font-size: 18px;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    @media (max-width: 1024px) {
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-4 {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .grid-3, .grid-4 {
        grid-template-columns: 1fr;
      }
      .section-title {
        font-size: 28px;
      }
    }

    .service-card, .case-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: transform 0.3s, box-shadow 0.3s;
    }

    .service-card:hover, .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .service-icon {
      width: 48px;
      height: 48px;
      background: rgba(232, 93, 4, 0.1);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent-orange);
      font-size: 24px;
      margin-bottom: 24px;
    }

    .service-card h3, .case-card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .service-card p, .case-card p {
      color: var(--text-secondary);
      margin-bottom: 20px;
      line-height: 1.6;
    }

    .text-link {
      color: var(--accent-orange);
      text-decoration: none;
      font-weight: 500;
      transition: border-bottom 0.2s;
    }

    .text-link:hover {
      border-bottom: 1px solid var(--accent-orange);
    }

    .case-img {
      width: 100%;
      height: 180px;
      object-fit: cover;
      border-radius: 8px;
      margin-bottom: 20px;
    }

    .tag {
      background: var(--secondary-warm);
      color: var(--text-secondary);
      padding: 4px 12px;
      border-radius: 4px;
      font-size: 13px;
      margin-right: 8px;
    }

    .data-section {
      background: var(--secondary-warm);
      border-top: 1px solid var(--border-light);
      border-bottom: 1px solid var(--border-light);
    }

    .stat-item {
      text-align: left;
    }

    .stat-number {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 700;
      color: var(--accent-orange);
    }

    .stat-label {
      color: var(--text-secondary);
      margin-top: 8px;
      font-size: 16px;
    }

    .faq-container {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
    }

    .faq-icon {
      font-size: 24px;
      color: var(--accent-orange);
      transition: transform 0.3s;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      line-height: 1.7;
      padding-top: 0;
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }

    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    .cta-block {
      background: var(--primary-dark);
      padding: 80px 0;
      text-align: center;
      color: white;
    }

    .cta-block h2 {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
    }

    .cta-block p {
      color: rgba(255,255,255,0.8);
      max-width: 600px;
      margin: 0 auto 32px;
    }

    .footer {
      background: var(--primary-deeper);
      color: rgba(255,255,255,0.7);
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 32px;
    }

    .footer h4 {
      color: white;
      margin-bottom: 20px;
      font-weight: 600;
    }

    .footer a {
      color: rgba(255,255,255,0.6);
      text-decoration: none;
      display: block;
      margin-bottom: 12px;
    }

    .footer a:hover {
      color: var(--accent-orange);
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .cta-block h2 {
        font-size: 28px;
      }
    }