/* roulang page: index */
:root {
      --primary: #1A3C34;
      --primary-deep: #0F2420;
      --accent: #C19A49;
      --accent-light: #d4af6a;
      --bg: #FAFAF8;
      --surface: #FFFFFF;
      --text-main: #1A1A1A;
      --text-soft: #4A4A4A;
      --text-muted: #8A8A8A;
      --border-light: rgba(26, 60, 52, 0.08);
      --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 12px 32px rgba(26, 60, 52, 0.12);
      --radius-card: 16px;
      --radius-btn: 50px;
      --font-serif: 'DM Serif Display', Georgia, 'Times New Roman', serif;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --transition-smooth: 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --container-max: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 40px;
    }
    h1, h2, h3, .serif {
      font-family: var(--font-serif);
      font-weight: 500;
      letter-spacing: -0.02em;
    }
    h2 {
      font-size: 2.5rem;
      margin-bottom: 1rem;
      color: var(--primary);
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-smooth);
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-sans);
      font-weight: 600;
      transition: all var(--transition-smooth);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border: none;
      outline: none;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      border: 2px solid var(--primary);
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      border-color: var(--primary-deep);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(26, 60, 52, 0.25);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      border: 2px solid var(--accent);
    }
    .btn-accent:hover {
      background: #a67c3a;
      border-color: #a67c3a;
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(193, 154, 73, 0.3);
    }
    .btn-outline-light {
      background: transparent;
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      border: 2px solid white;
    }
    .btn-outline-light:hover {
      background: white;
      color: var(--primary);
      transform: translateY(-2px);
    }
    section {
      padding: 100px 0;
    }
    /* 导航 */
    .nav-bar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      z-index: 999;
      transition: box-shadow var(--transition-smooth), background var(--transition-smooth);
      border-bottom: 1px solid transparent;
    }
    .nav-bar.scrolled {
      background: rgba(255, 255, 255, 0.98);
      box-shadow: 0 6px 20px rgba(0,0,0,0.04);
      border-bottom: 1px solid rgba(26,60,52,0.08);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 76px;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 40px;
    }
    .logo {
      font-family: var(--font-serif);
      font-size: 1.8rem;
      font-weight: 500;
      color: var(--primary);
      letter-spacing: 0.5px;
      display: flex;
      align-items: baseline;
      gap: 6px;
    }
    .logo span {
      font-family: var(--font-sans);
      font-size: 0.9rem;
      font-weight: 500;
      letter-spacing: 0.8px;
      color: var(--accent);
    }
    .nav-links {
      display: flex;
      gap: 2.2rem;
      align-items: center;
      font-weight: 500;
      color: var(--text-soft);
    }
    .nav-links a {
      position: relative;
      padding: 8px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition-smooth);
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 26px;
      height: 2px;
      background: var(--primary);
      transition: var(--transition-smooth);
    }
    /* Hero */
    .hero {
      height: 100vh;
      min-height: 700px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(15,36,32,0.82) 0%, rgba(15,36,32,0.55) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
      color: white;
    }
    .hero h1 {
      font-size: clamp(2.5rem, 6vw, 3.8rem);
      line-height: 1.2;
      margin-bottom: 1.5rem;
      color: white;
    }
    .hero p {
      font-size: 1.2rem;
      opacity: 0.9;
      margin-bottom: 2.2rem;
    }
    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }
    .floating-badge {
      position: absolute;
      right: 6%;
      bottom: 12%;
      background: rgba(15, 36, 32, 0.75);
      backdrop-filter: blur(8px);
      padding: 1.2rem 2rem;
      border-radius: 20px;
      color: white;
      display: flex;
      gap: 2rem;
      font-weight: 500;
      border-left: 4px solid var(--accent);
    }
    /* 优势 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      margin-top: 40px;
    }
    .adv-item {
      background: var(--surface);
      padding: 36px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
      text-align: center;
    }
    .adv-item:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .adv-icon {
      font-size: 2.6rem;
      color: var(--accent);
      margin-bottom: 20px;
    }
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      margin-top: 40px;
    }
    .service-card {
      background: var(--surface);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
    }
    .service-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }
    .service-img {
      height: 220px;
      object-fit: cover;
    }
    .service-body {
      padding: 28px 24px;
    }
    /* 数据 */
    .dark-section {
      background: var(--primary-deep);
      color: white;
      padding: 90px 0;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }
    .stat-number {
      font-size: 3.5rem;
      font-weight: 700;
      color: var(--accent);
      font-family: var(--font-serif);
    }
    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      margin-top: 40px;
    }
    .case-card {
      background: var(--surface);
      border-radius: 16px 16px 0 16px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
    }
    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .process-steps {
      display: flex;
      justify-content: space-between;
      margin-top: 50px;
      position: relative;
    }
    .process-steps::before {
      content: '';
      position: absolute;
      top: 24px;
      left: 5%;
      width: 90%;
      height: 2px;
      background: var(--accent);
      opacity: 0.4;
    }
    .step {
      text-align: center;
      flex:1;
      position: relative;
    }
    .step-num {
      background: var(--accent);
      color: white;
      width: 48px;
      height: 48px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px;
      font-weight: 700;
      font-size: 1.3rem;
    }
    /* FAQ */
    .faq-item {
      background: var(--surface);
      border-radius: 16px;
      margin-bottom: 16px;
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
      border-left: 4px solid var(--accent);
      transition: var(--transition-smooth);
    }
    .faq-question {
      padding: 24px 28px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      padding: 0 28px 24px;
      color: var(--text-soft);
      background: #F2F6F4;
      margin: 0 12px 12px;
      border-radius: 12px;
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .footer {
      background: var(--primary-deep);
      color: rgba(255,255,255,0.8);
      padding: 70px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1.5fr 1.2fr;
      gap: 40px;
    }
    @media (max-width: 1024px) {
      .advantages-grid, .services-grid, .cases-grid { grid-template-columns: repeat(2,1fr); }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .container { padding: 0 20px; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero h1 { font-size: 2.2rem; }
      .floating-badge { position: static; margin-top: 24px; width: fit-content; }
      .advantages-grid, .services-grid, .cases-grid { grid-template-columns: 1fr; }
      .process-steps { flex-direction: column; gap: 30px; }
      .process-steps::before { display: none; }
      .footer-grid { grid-template-columns: 1fr; }
      section { padding: 70px 0; }
    }
    .mobile-menu {
      position: fixed;
      top: 76px;
      left: 0;
      width: 100%;
      background: #FAFAF8;
      flex-direction: column;
      padding: 32px;
      gap: 24px;
      display: none;
      z-index: 998;
      box-shadow: 0 20px 30px rgba(0,0,0,0.05);
    }
    .mobile-menu.active { display: flex; }
    .mobile-menu a { font-size: 1.2rem; font-weight: 500; }