/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --windsor-green: #2E4A3E;
      --parchment-warm: #F7F3EB;
      --burgundy-red: #8B3A3A;
      --charcoal-dark: #1E1E1E;
      --slate-gray: #6B6B6B;
      --light-gray: #E8E4DE;
      --white: #FFFFFF;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 28px rgba(0,0,0,0.08);
      --radius-lg: 8px;
      --radius-sm: 6px;
      --radius-btn: 6px;
      --font-title: 'Playfair Display', 'Times New Roman', serif;
      --font-body: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --font-ui: 'DM Sans', 'Inter', sans-serif;
      --transition-fast: 0.25s ease-out;
      --transition-smooth: 0.4s ease-out;
      --container-max: 1280px;
    }

    /* ----- 基础重置 ----- */
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; font-size: 16px; }
    body {
      font-family: var(--font-body);
      background-color: var(--parchment-warm);
      color: var(--charcoal-dark);
      line-height: 1.7;
      overflow-x: hidden;
    }
    img { display: block; max-width: 100%; height: auto; }
    a { text-decoration: none; color: inherit; transition: color var(--transition-fast); }
    ul { list-style: none; }
    button, input, textarea { font-family: inherit; font-size: inherit; outline: none; border: none; background: none; }
    .container { max-width: var(--container-max); margin: 0 auto; padding: 0 24px; }

    /* ----- 顶部信息条 ----- */
    .top-bar {
      background: var(--windsor-green);
      color: var(--parchment-warm);
      font-size: 12px;
      font-family: var(--font-ui);
      height: 36px;
      display: flex;
      align-items: center;
    }
    .top-bar .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .top-bar-left span { opacity: 0.9; }
    .top-bar-right { display: flex; align-items: center; gap: 12px; }
    .top-bar-cta {
      color: var(--parchment-warm);
      background: rgba(255,255,255,0.1);
      padding: 4px 12px;
      border-radius: 4px;
      font-weight: 600;
      transition: background var(--transition-fast);
    }
    .top-bar-cta:hover { background: rgba(255,255,255,0.2); }
    .top-bar-phone { font-weight: 500; letter-spacing: 0.02em; }

    /* ----- 主导航 ----- */
    .main-nav {
      background: var(--white);
      height: 72px;
      display: flex;
      align-items: center;
      position: sticky;
      top: 0;
      z-index: 50;
      box-shadow: 0 1px 6px rgba(0,0,0,0.02);
      transition: box-shadow var(--transition-fast);
    }
    .main-nav.scrolled { box-shadow: 0 4px 20px rgba(0,0,0,0.05); }
    .main-nav .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-family: var(--font-title);
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--windsor-green);
      letter-spacing: 0.03em;
      white-space: nowrap;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 0.938rem;
      font-weight: 500;
      color: var(--charcoal-dark);
      padding: 4px 0;
      position: relative;
      transition: color var(--transition-fast);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--windsor-green);
      transition: width var(--transition-smooth);
    }
    .nav-links a:hover { color: var(--windsor-green); }
    .nav-links a:hover::after,
    .nav-links a.active::after { width: 100%; }
    .nav-links a.active { color: var(--windsor-green); }

    /* 汉堡菜单 */
    .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; background: none; }
    .hamburger span { width: 24px; height: 2.5px; background: var(--charcoal-dark); border-radius: 2px; transition: all var(--transition-fast); }
    .hamburger.open span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
    .hamburger.open span:nth-child(2) { opacity: 0; }
    .hamburger.open span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

    @media (max-width: 767px) {
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: var(--parchment-warm);
        flex-direction: column;
        align-items: center;
        padding: 24px;
        gap: 20px;
        display: none;
        box-shadow: 0 12px 24px rgba(0,0,0,0.05);
      }
      .nav-links.mobile-open { display: flex; }
      .hamburger { display: flex; }
    }

    /* ----- Hero 双栏 ----- */
    .hero {
      padding: 60px 0 80px;
      background: var(--white);
    }
    .hero .container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-left h1 {
      font-family: var(--font-title);
      font-size: 3rem;
      line-height: 1.15;
      color: var(--charcoal-dark);
      margin-bottom: 16px;
    }
    .hero-left .subtitle {
      font-size: 1.125rem;
      color: var(--slate-gray);
      max-width: 480px;
      margin-bottom: 32px;
    }
    .hero-buttons { display: flex; gap: 20px; flex-wrap: wrap; margin-bottom: 40px; }
    .btn-primary {
      background: var(--burgundy-red);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-family: var(--font-ui);
      transition: all var(--transition-fast);
      display: inline-block;
    }
    .btn-primary:hover { background: #6E2E2E; transform: translateY(-2px); box-shadow: 0 6px 16px rgba(139,58,58,0.3); }
    .btn-secondary {
      background: transparent;
      color: var(--windsor-green);
      border: 1.5px solid var(--windsor-green);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-family: var(--font-ui);
      transition: all var(--transition-fast);
    }
    .btn-secondary:hover { background: var(--windsor-green); color: white; }
    .hero-stats {
      display: flex;
      gap: 40px;
    }
    .hero-stat h3 {
      font-family: var(--font-title);
      font-size: 2.25rem;
      color: var(--windsor-green);
    }
    .hero-stat p {
      font-size: 0.75rem;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      color: var(--slate-gray);
    }
    .hero-right {
      position: relative;
    }
    .hero-right img {
      width: 100%;
      border-radius: 4px;
      aspect-ratio: 4/5;
      object-fit: cover;
      box-shadow: var(--shadow-sm);
    }
    .hero-right::after {
      content: '';
      position: absolute;
      right: -14px;
      top: 10px;
      width: 4px;
      height: 60%;
      background: var(--windsor-green);
      border-radius: 2px;
    }
    @media (max-width: 1023px) {
      .hero .container { grid-template-columns: 1fr; }
      .hero-right { max-width: 500px; margin: 0 auto; }
    }
    @media (max-width: 520px) {
      .hero-left h1 { font-size: 2.2rem; }
      .hero-stats { gap: 20px; }
    }

    /* ----- 区块标题 ----- */
    .section { padding: 80px 0; }
    .section-dark { background: var(--windsor-green); color: white; }
    .section-title {
      font-family: var(--font-title);
      font-size: 2.25rem;
      margin-bottom: 16px;
      color: var(--charcoal-dark);
    }
    .section-dark .section-title { color: white; }
    .section-sub {
      font-size: 1.05rem;
      color: var(--slate-gray);
      margin-bottom: 48px;
    }

    /* ----- 亮点网格 ----- */
    .highlight-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 24px;
      margin-top: 32px;
    }
    .highlight-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      transition: box-shadow var(--transition-fast);
    }
    .highlight-card:hover { box-shadow: var(--shadow-hover); }
    .highlight-large { border-left: 4px solid var(--windsor-green); }
    .highlight-small { text-align: center; }
    .highlight-small .icon { font-size: 2rem; margin-bottom: 12px; }
    .highlight-number {
      font-family: var(--font-title);
      font-size: 2rem;
      color: var(--windsor-green);
    }
    @media (max-width: 768px) {
      .highlight-grid { grid-template-columns: 1fr 1fr; }
      .highlight-large { grid-column: span 2; }
    }
    @media (max-width: 520px) {
      .highlight-grid { grid-template-columns: 1fr; }
      .highlight-large { grid-column: span 1; }
    }

    /* ----- 核心业务卡片 ----- */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 24px;
    }
    .service-card {
      background: var(--white);
      padding: 28px;
      border-radius: var(--radius-sm);
      display: flex;
      gap: 20px;
      align-items: flex-start;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition-fast);
      border-left: 4px solid var(--light-gray);
    }
    .service-card:hover {
      border-left-color: var(--windsor-green);
      box-shadow: var(--shadow-hover);
    }
    .service-icon {
      width: 36px;
      height: 36px;
      background: var(--light-gray);
      border-radius: 4px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--windsor-green);
    }
    .service-content h3 { font-size: 1.25rem; margin-bottom: 8px; }
    .service-content p { font-size: 0.875rem; color: var(--slate-gray); }
    @media (max-width: 768px) { .services-grid { grid-template-columns: 1fr 1fr; } }
    @media (max-width: 520px) { .services-grid { grid-template-columns: 1fr; } }

    /* ----- 案例瀑布流 ----- */
    .case-grid {
      display: grid;
      grid-template-columns: 5fr 4fr;
      gap: 24px;
    }
    .case-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: box-shadow var(--transition-fast);
    }
    .case-card:hover { box-shadow: var(--shadow-hover); }
    .case-card img {
      width: 100%;
      aspect-ratio: 3/2;
      object-fit: cover;
      transition: transform var(--transition-smooth);
    }
    .case-card:hover img { transform: scale(1.03); }
    .case-info {
      padding: 20px;
    }
    .case-tag {
      background: var(--burgundy-red);
      color: white;
      font-size: 0.688rem;
      padding: 4px 10px;
      border-radius: 4px;
      display: inline-block;
      margin-bottom: 8px;
    }
    .case-title { font-size: 1.25rem; margin-bottom: 6px; }
    .case-desc { font-size: 0.875rem; color: var(--slate-gray); }
    @media (max-width: 768px) { .case-grid { grid-template-columns: 1fr 1fr; } }
    @media (max-width: 520px) { .case-grid { grid-template-columns: 1fr; } }

    /* ----- 方案对比 ----- */
    .comparison-row {
      display: grid;
      grid-template-columns: 1fr 30px 1fr;
      align-items: stretch;
      margin-top: 40px;
    }
    .compare-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
    }
    .compare-card.right {
      background: #F4F0E8;
      box-shadow: 0 0 0 1px var(--windsor-green), var(--shadow-sm);
    }
    .compare-divider {
      width: 1px;
      background: var(--light-gray);
      margin: 0 auto;
    }
    .compare-tag {
      background: var(--windsor-green);
      color: white;
      font-size: 0.75rem;
      padding: 4px 12px;
      border-radius: 4px;
      display: inline-block;
      margin-bottom: 16px;
    }
    .compare-list li {
      margin-bottom: 10px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    @media (max-width: 768px) { .comparison-row { grid-template-columns: 1fr; gap: 24px; } .compare-divider { display: none; } }

    /* ----- FAQ 手风琴 ----- */
    .faq-list {
      max-width: 800px;
      margin: 32px auto 0;
    }
    .faq-item {
      border-bottom: 1px solid var(--light-gray);
      padding: 18px 0;
      cursor: pointer;
    }
    .faq-question {
      font-size: 1.125rem;
      font-weight: 500;
      display: flex;
      justify-content: space-between;
      transition: color var(--transition-fast);
    }
    .faq-item.open .faq-question { color: var(--windsor-green); font-weight: 600; border-left: 3px solid var(--windsor-green); padding-left: 16px; }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: all var(--transition-smooth);
      color: var(--slate-gray);
      padding-left: 19px;
    }
    .faq-item.open .faq-answer { max-height: 200px; margin-top: 12px; color: var(--charcoal-dark); }

    /* ----- 联系 CTA ----- */
    .cta-section {
      background: var(--charcoal-dark);
      color: white;
      text-align: center;
    }
    .cta-form {
      max-width: 600px;
      margin: 32px auto 0;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .cta-form input, .cta-form textarea {
      background: white;
      border-bottom: 1px solid #CCC;
      padding: 12px;
      border-radius: 4px;
      transition: border var(--transition-fast);
    }
    .cta-form input:focus, .cta-form textarea:focus {
      border-bottom: 2px solid var(--windsor-green);
    }
    .btn-submit {
      background: var(--burgundy-red);
      color: white;
      padding: 14px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: all var(--transition-fast);
    }
    .btn-submit:hover { background: #6E2E2E; transform: translateY(-2px); }

    /* ----- 页脚 ----- */
    .footer {
      background: var(--charcoal-dark);
      color: #B0B0B0;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
      margin-bottom: 32px;
    }
    .footer h4 { color: white; font-weight: 600; margin-bottom: 12px; }
    .footer a:hover { color: var(--windsor-green); }
    .copyright {
      border-top: 1px solid #444;
      padding-top: 20px;
      text-align: center;
      font-size: 0.875rem;
    }
    @media (max-width: 768px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
    @media (max-width: 520px) { .footer-grid { grid-template-columns: 1fr; } }