/* roulang page: index */
:root {
      --color-primary: #C77A2D;
      --color-primary-hover: #A86522;
      --color-secondary: #4A3B32;
      --color-bg: #FAF7F2;
      --color-accent: #D4956A;
      --color-text: #2C2416;
      --color-text-weak: #8C7B6A;
      --color-gray-light: #F0EBE3;
      --color-border: #D6CDC0;
      --color-white: #FFFFFF;
      --radius-card: 8px;
      --radius-btn: 6px;
      --shadow-sm: 0 2px 12px rgba(44,36,22,0.06);
      --shadow-hover: 0 8px 24px rgba(44,36,22,0.12);
      --font-serif: 'Noto Serif SC', 'Times New Roman', serif;
      --font-sans: 'Noto Sans SC', 'Helvetica Neue', sans-serif;
      --font-mono: 'Inter', 'Noto Sans SC', sans-serif;
      --spacing-section: 5rem;
      --max-width: 75rem;
    }

    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; font-size: 100%; }
    body {
      font-family: var(--font-sans);
      background-color: var(--color-bg);
      color: var(--color-text);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img { max-width: 100%; height: auto; display: block; }
    a { text-decoration: none; color: inherit; }
    button, input { font-family: inherit; }

    .container { max-width: var(--max-width); margin: 0 auto; padding: 0 1.5rem; }
    .section-padding { padding: var(--spacing-section) 0; }

    h1, h2, h3, h4 { font-family: var(--font-serif); font-weight: 700; line-height: 1.3; }
    h1 { font-size: 3rem; color: var(--color-text); }
    h2 { font-size: 2.25rem; color: var(--color-text); margin-bottom: 1.5rem; }
    h3 { font-size: 1.5rem; color: var(--color-text); }
    p { font-size: 1rem; color: var(--color-text); margin-bottom: 1rem; }
    .text-weak { color: var(--color-text-weak); font-size: 0.9rem; }

    .btn {
      display: inline-flex; align-items: center; justify-content: center;
      padding: 0.875rem 2rem; border-radius: var(--radius-btn);
      font-weight: 500; font-size: 1rem; transition: all 0.25s ease;
      cursor: pointer; border: none; line-height: 1.2;
    }
    .btn-primary {
      background: var(--color-primary); color: #FFFFFF;
      box-shadow: 0 2px 8px rgba(199,122,45,0.25);
    }
    .btn-primary:hover { background: var(--color-primary-hover); box-shadow: 0 4px 14px rgba(199,122,45,0.35); color: #fff; }
    .btn-outline {
      background: transparent; border: 1.5px solid var(--color-primary); color: var(--color-primary);
    }
    .btn-outline:hover { background: var(--color-primary); color: #FFFFFF; }

    .card {
      background: var(--color-white); border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm); transition: all 0.3s ease;
    }
    .card:hover { transform: translateY(-2px); box-shadow: var(--shadow-hover); }

    /* 导航栏 */
    .site-header {
      position: sticky; top: 0; z-index: 50;
      background: var(--color-bg); border-bottom: 1px solid rgba(0,0,0,0.04);
      box-shadow: 0 1px 6px rgba(0,0,0,0.03);
    }
    .nav-container {
      display: flex; align-items: center; justify-content: space-between;
      padding: 0.75rem 1.5rem; max-width: var(--max-width); margin: 0 auto;
    }
    .logo {
      font-family: var(--font-serif); font-weight: 700; font-size: 1.5rem;
      color: var(--color-primary); white-space: nowrap;
    }
    .search-box {
      flex: 1; max-width: 28rem; margin: 0 2rem; position: relative;
    }
    .search-box input {
      width: 100%; padding: 0.65rem 1.2rem 0.65rem 2.8rem;
      border: 1px solid var(--color-border); border-radius: 24px;
      background: var(--color-white); font-size: 0.9rem; outline: none;
      transition: all 0.2s;
    }
    .search-box input:focus { border-color: var(--color-primary); box-shadow: 0 0 0 3px rgba(199,122,45,0.15); }
    .search-icon {
      position: absolute; left: 1rem; top: 50%; transform: translateY(-50%);
      color: var(--color-primary); font-size: 1.1rem;
    }
    .nav-links { display: flex; gap: 2rem; align-items: center; }
    .nav-links a { font-weight: 500; font-size: 0.95rem; color: var(--color-text); transition: color 0.2s; }
    .nav-links a:hover { color: var(--color-primary); }

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

    /* Hero */
    .hero-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; align-items: center; }
    .hero-text { animation: fadeUp 0.8s ease forwards; }
    .hero-image { animation: fadeRight 0.8s ease forwards; }
    .hero-image img { border-radius: 12px; box-shadow: 0 8px 30px rgba(0,0,0,0.08); width: 100%; height: auto; object-fit: cover; }

    @keyframes fadeUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
    @keyframes fadeRight { from { opacity: 0; transform: translateX(20px); } to { opacity: 1; transform: translateX(0); } }

    /* 服务不对称布局 */
    .asymmetric-grid { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 2rem; }
    .big-image img { width: 100%; height: 100%; object-fit: cover; border-radius: 10px; }
    .service-cards { display: flex; flex-direction: column; gap: 2rem; }
    .service-card {
      background: var(--color-white); border-radius: var(--radius-card);
      padding: 2rem; box-shadow: var(--shadow-sm);
      border-left: 4px solid var(--color-primary);
    }

    /* 数据条 */
    .stats-strip {
      background: var(--color-gray-light); border-radius: 12px;
      display: grid; grid-template-columns: repeat(4,1fr); gap: 2rem;
      padding: 2.5rem 2rem; text-align: center;
    }
    .stat-number { font-family: var(--font-mono); font-weight: 700; font-size: 3.5rem; color: var(--color-primary); }
    .stat-label { font-size: 0.9rem; color: var(--color-secondary); margin-top: 0.5rem; }

    /* 案例 */
    .cases-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; }
    .case-card { overflow: hidden; }
    .case-img { height: 280px; overflow: hidden; }
    .case-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s ease; }
    .case-card:hover .case-img img { transform: scale(1.03); }
    .case-body { padding: 1.5rem 2rem; display: flex; justify-content: space-between; align-items: center; }
    .arrow-icon { transition: transform 0.25s; color: var(--color-primary); }
    .case-card:hover .arrow-icon { transform: translateX(4px); }

    /* 流程条 */
    .steps-row { display: flex; justify-content: space-between; align-items: flex-start; position: relative; margin-top: 2rem; }
    .step-item { text-align: center; flex: 1; position: relative; }
    .step-circle { width: 48px; height: 48px; background: var(--color-primary); color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; margin: 0 auto 1rem; font-weight: 700; font-size: 1.2rem; }
    .step-line { position: absolute; top: 24px; left: 65%; width: 70%; border-top: 2px dashed var(--color-border); z-index: 0; }
    .step-item:last-child .step-line { display: none; }

    /* FAQ */
    .faq-item { border-bottom: 1px solid var(--color-border); background: var(--color-white); }
    .faq-question {
      padding: 1.2rem 1.5rem; cursor: pointer; font-weight: 500; font-size: 1.1rem;
      display: flex; justify-content: space-between; align-items: center;
      transition: background 0.2s;
    }
    .faq-item.active .faq-question { background: #FAF7F2; border-left: 3px solid var(--color-primary); }
    .faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.35s ease; padding: 0 1.5rem; background: #FAF7F2; }
    .faq-item.active .faq-answer { max-height: 20rem; padding: 1rem 1.5rem; }
    .faq-icon { font-size: 1.4rem; color: var(--color-primary); }

    /* CTA 横幅 */
    .cta-banner { background: var(--color-secondary); color: #fff; text-align: center; padding: 4rem 2rem; border-radius: 12px; }
    .cta-banner h2 { color: #fff; }
    .btn-cta { border: 1.5px solid #fff; color: #fff; background: transparent; }
    .btn-cta:hover { background: var(--color-primary); border-color: var(--color-primary); }

    /* 页脚 */
    .site-footer { background: var(--color-secondary); color: #D6CDC0; padding: 3rem 0 1.5rem; margin-top: 3rem; }
    .footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 2rem; }
    .footer-logo { font-family: var(--font-serif); font-size: 1.4rem; color: #fff; }
    .footer-links a { display: block; color: #D6CDC0; margin-bottom: 0.5rem; transition: color 0.2s; }
    .footer-links a:hover { color: var(--color-accent); }
    .copyright { border-top: 1px solid rgba(255,255,255,0.1); margin-top: 2rem; padding-top: 1.5rem; text-align: center; font-size: 0.9rem; }

    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .asymmetric-grid { grid-template-columns: 1fr; }
      .cases-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .search-box { max-width: 20rem; }
    }
    @media (max-width: 768px) {
      h1 { font-size: 2rem; } h2 { font-size: 1.8rem; }
      .nav-links { display: none; }
      .hamburger { display: block; }
      .search-box { margin: 0 1rem; }
      .stats-strip { grid-template-columns: 1fr 1fr; }
      .steps-row { flex-direction: column; gap: 2rem; }
      .step-line { display: none; }
    }
    @media (max-width: 520px) {
      .footer-grid { grid-template-columns: 1fr; }
      .stats-strip { grid-template-columns: 1fr; }
      .btn { padding: 0.75rem 1.5rem; }
    }