/* roulang page: index */
* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    :root {
      --primary: #D42E12;
      --primary-dark: #A8230D;
      --accent: #C8A45C;
      --bg-dark: #0D0D0D;
      --bg-light: #F5F1EB;
      --text-primary: #1A1A1A;
      --text-secondary: #5C5C5C;
      --text-inverse: #FFFFFF;
      --card-bg-light: #FFFFFF;
      --card-bg-dark: rgba(255,255,255,0.05);
      --border-light: rgba(0,0,0,0.06);
      --border-accent: rgba(200,164,92,0.2);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.08);
      --shadow-hover: 0 8px 32px rgba(0,0,0,0.15);
      --container-max: 1280px;
      --nav-height: 72px;
      --font-family: 'Noto Sans SC', sans-serif;
    }
    body {
      font-family: var(--font-family);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input, textarea {
      font-family: inherit;
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(13,13,13,0.85);
      backdrop-filter: blur(12px);
      z-index: 1000;
      transition: background 0.3s, box-shadow 0.3s;
      display: flex;
      align-items: center;
    }
    .navbar.scrolled {
      background: #0D0D0D;
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
      border-bottom: 1px solid var(--accent);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--accent);
      letter-spacing: -0.5px;
      white-space: nowrap;
    }
    .logo span {
      color: var(--text-inverse);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-menu a {
      color: var(--text-inverse);
      font-weight: 500;
      font-size: 16px;
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s;
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }
    .nav-cta {
      background: var(--primary);
      color: white;
      padding: 10px 20px;
      border-radius: 8px;
      font-weight: 600;
      transition: background 0.2s, transform 0.2s;
      display: inline-block;
    }
    .nav-cta:hover {
      background: var(--primary-dark);
      transform: scale(1.03);
    }
    .hamburger {
      display: none;
      font-size: 28px;
      color: white;
      cursor: pointer;
      background: none;
      border: none;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: var(--nav-height);
      left: 0;
      width: 100%;
      height: calc(100vh - var(--nav-height));
      background: #0D0D0D;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 28px;
      z-index: 999;
    }
    .mobile-menu a {
      color: white;
      font-size: 22px;
      font-weight: 600;
    }
    .mobile-menu .nav-cta {
      margin-top: 16px;
    }

    /* 首屏 Hero */
    .hero {
      height: 100vh;
      min-height: 700px;
      background: var(--bg-dark) url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
      color: white;
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at center, transparent 30%, rgba(0,0,0,0.7) 90%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
      text-align: left;
    }
    .hero h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 900;
      text-shadow: 0 0 20px rgba(200,164,92,0.5);
      margin-bottom: 20px;
    }
    .hero h1 .gold {
      color: var(--accent);
    }
    .hero p {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      margin-bottom: 36px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 36px;
      border-radius: 8px;
      font-weight: 600;
      border: none;
      transition: background 0.2s, transform 0.2s;
      display: inline-block;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.03);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 14px 36px;
      border-radius: 8px;
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-secondary:hover {
      background: white;
      color: var(--bg-dark);
    }
    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      left: 50%;
      transform: translateX(-50%);
      font-size: 32px;
      color: var(--accent);
      animation: pulse 2s infinite;
      z-index: 2;
    }
    @keyframes pulse {
      0% { opacity: 0.6; transform: translateX(-50%) translateY(0); }
      50% { opacity: 1; transform: translateX(-50%) translateY(8px); }
      100% { opacity: 0.6; transform: translateX(-50%) translateY(0); }
    }

    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 48px;
      position: relative;
      padding-left: 20px;
    }
    .section-title::before {
      content: '';
      position: absolute;
      left: 0;
      top: 50%;
      transform: translateY(-50%);
      width: 4px;
      height: 36px;
      background: var(--primary);
      border-radius: 2px;
    }
    .bg-light {
      background: var(--bg-light);
    }
    .bg-white {
      background: #FFFFFF;
    }
    .bg-dark {
      background: var(--bg-dark);
      color: white;
    }
    .bg-dark .section-title {
      color: white;
    }

    /* 优势卡片 */
    .strength-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .strength-card {
      background: white;
      padding: 32px;
      border-radius: var(--radius-md);
      text-align: center;
      border-bottom: 3px solid var(--primary);
      transition: 0.3s;
    }
    .strength-card:hover {
      border-bottom-width: 6px;
      transform: translateY(-4px);
    }
    .strength-number {
      font-size: 42px;
      font-weight: 900;
      color: var(--accent);
    }

    /* 服务非对称 */
    .service-row {
      display: flex;
      gap: 48px;
      align-items: center;
      margin-bottom: 64px;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 5;
      border-radius: var(--radius-lg);
      overflow: hidden;
    }
    .service-text {
      flex: 7;
    }
    .service-number {
      font-size: 48px;
      font-weight: 900;
      color: var(--accent);
      opacity: 0.7;
    }

    /* 案例网格 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .case-card {
      background: rgba(255,255,255,0.03);
      border: 1px solid var(--border-accent);
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: 0.3s;
    }
    .case-card:hover {
      border-color: var(--accent);
      transform: translateY(-4px);
    }
    .case-info {
      padding: 16px;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
    }

    /* CTA 表单 */
    .cta-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .contact-form input, .contact-form textarea {
      width: 100%;
      background: rgba(255,255,255,0.05);
      border: 1px solid rgba(255,255,255,0.15);
      border-radius: 8px;
      padding: 12px;
      color: white;
      margin-bottom: 16px;
    }
    .contact-form input:focus, .contact-form textarea:focus {
      border-color: var(--accent);
      outline: none;
    }
    .btn-accent {
      background: var(--accent);
      color: #0D0D0D;
      font-weight: 600;
      padding: 14px;
      width: 100%;
      border: none;
      border-radius: 8px;
      cursor: pointer;
    }

    /* 页脚 */
    .footer {
      background: #0A0A0A;
      color: rgba(255,255,255,0.6);
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .strength-grid { grid-template-columns: repeat(2, 1fr); }
      .case-grid { grid-template-columns: repeat(2, 1fr); }
      .service-row { flex-direction: column; }
      .service-row.reverse { flex-direction: column; }
      .cta-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: block; }
      .hero h1 { font-size: 32px; }
      section { padding: 60px 0; }
      .strength-grid { grid-template-columns: 1fr; }
      .case-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
    }