/* roulang page: index */
:root {
      --deep-stone: #2B2D2F;
      --sandstone-gold: #C8A96E;
      --sandstone-dark: #B3924F;
      --cloud-white: #F7F5F0;
      --pure-white: #FFFFFF;
      --border-light: #E8E5DF;
      --text-gray: #6B6D6F;
      --text-dark: #2B2D2F;
      --success-green: #2E7D5C;
      --alert-red: #B13E3C;
      --shadow-sm: 0 2px 12px rgba(43,45,47,0.06);
      --shadow-md: 0 6px 24px rgba(43,45,47,0.12);
      --radius-sm: 4px;
      --radius-md: 8px;
      --font-serif: "Noto Serif SC", "Source Han Serif SC", serif;
      --font-sans: "Noto Sans SC", "PingFang SC", "Helvetica Neue", sans-serif;
      --font-mono: "DM Mono", "Fira Code", monospace;
      --transition: 0.3s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--cloud-white);
      color: var(--text-dark);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 40px;
    }
    h1, h2, h3 {
      font-family: var(--font-serif);
      font-weight: 700;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, input, textarea {
      font-family: inherit;
    }

    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background-color var(--transition), backdrop-filter var(--transition);
      background-color: transparent;
      padding: 20px 0;
    }
    .header.scrolled {
      background-color: var(--deep-stone);
      box-shadow: 0 2px 12px rgba(0,0,0,0.1);
      padding: 14px 0;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 40px;
    }
    .logo {
      font-family: var(--font-serif);
      font-size: 22px;
      font-weight: 700;
      color: var(--sandstone-gold);
      letter-spacing: 1px;
      z-index: 1001;
    }
    .nav-links {
      display: flex;
      gap: 36px;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      color: var(--cloud-white);
      font-size: 15px;
      font-weight: 500;
      transition: color var(--transition);
      position: relative;
      padding: 4px 0;
    }
    .nav-links a::after {
      content: "";
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 1.5px;
      background-color: var(--sandstone-gold);
      transition: width var(--transition);
    }
    .nav-links a:hover {
      color: var(--sandstone-gold);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .mega-trigger {
      position: relative;
      cursor: pointer;
    }
    .mega-panel {
      position: absolute;
      top: 100%;
      left: -40px;
      width: 320px;
      background: var(--pure-white);
      box-shadow: var(--shadow-md);
      border-radius: var(--radius-md);
      padding: 20px;
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      opacity: 0;
      visibility: hidden;
      transform: translateY(10px);
      transition: all var(--transition);
      z-index: 999;
      border: 1px solid var(--border-light);
    }
    .mega-trigger:hover .mega-panel {
      opacity: 1;
      visibility: visible;
      transform: translateY(0);
    }
    .mega-item {
      flex: 1 1 40%;
      background: var(--cloud-white);
      padding: 12px;
      border-radius: var(--radius-sm);
      text-align: center;
      color: var(--deep-stone);
      font-weight: 500;
      transition: all var(--transition);
      border: 1.5px solid transparent;
      font-size: 14px;
    }
    .mega-item:hover {
      border-color: var(--sandstone-gold);
      background: white;
      color: var(--sandstone-dark);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      z-index: 1001;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--sandstone-gold);
      transition: var(--transition);
    }
    #menu-toggle {
      display: none;
    }
    #menu-toggle:checked ~ .mobile-menu {
      display: flex;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--deep-stone);
      flex-direction: column;
      justify-content: center;
      align-items: flex-start;
      padding: 40px;
      gap: 32px;
      z-index: 1000;
      list-style: none;
    }
    .mobile-menu a {
      color: var(--cloud-white);
      font-size: 22px;
      font-weight: 500;
      border-bottom: 1px solid rgba(255,255,255,0.15);
      width: 100%;
      padding-bottom: 8px;
    }

    /* 通用区块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      color: var(--deep-stone);
      margin-bottom: 16px;
    }
    .section-subtitle {
      font-size: 16px;
      color: var(--text-gray);
      margin-bottom: 48px;
    }
    .btn {
      display: inline-block;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 15px;
      transition: all var(--transition);
      cursor: pointer;
      text-align: center;
    }
    .btn-primary {
      background: var(--sandstone-gold);
      color: var(--deep-stone);
      border: none;
    }
    .btn-primary:hover {
      background: var(--sandstone-dark);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--sandstone-gold);
      color: var(--sandstone-gold);
    }
    .btn-outline:hover {
      background: rgba(200,169,110,0.1);
      transform: translateY(-2px);
    }
    .btn-light {
      background: var(--deep-stone);
      color: var(--cloud-white);
      border: none;
    }
    .btn-light:hover {
      background: #1f2122;
    }

    /* Hero */
    .hero {
      height: 100vh;
      background-color: var(--deep-stone);
      background-image: radial-gradient(circle at 20% 30%, rgba(255,255,255,0.03) 1px, transparent 1px);
      background-size: 40px 40px;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero-content {
      display: flex;
      align-items: center;
      gap: 60px;
      width: 100%;
    }
    .hero-text {
      flex: 0 0 55%;
    }
    .hero-tag {
      font-size: 14px;
      letter-spacing: 4px;
      color: var(--sandstone-gold);
      text-transform: uppercase;
      margin-bottom: 20px;
    }
    .hero h1 {
      font-size: 48px;
      color: var(--cloud-white);
      line-height: 1.2;
      margin-bottom: 24px;
    }
    .hero-desc {
      font-size: 18px;
      color: rgba(247,245,240,0.8);
      line-height: 1.8;
      margin-bottom: 40px;
      max-width: 540px;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
    }
    .hero-image {
      flex: 0 0 45%;
      position: relative;
    }
    .hero-image img {
      width: 100%;
      height: auto;
      border-radius: var(--radius-md);
      mask-image: linear-gradient(to right, rgba(0,0,0,0.4) 0%, rgba(0,0,0,1) 100%);
      -webkit-mask-image: linear-gradient(to right, rgba(0,0,0,0.4) 0%, rgba(0,0,0,1) 100%);
    }

    /* 优势非对称 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .adv-card {
      background: var(--pure-white);
      padding: 32px;
      border-radius: var(--radius-md);
      border-left: 4px solid var(--sandstone-gold);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid var(--border-light);
      border-left: 4px solid var(--sandstone-gold);
    }
    .adv-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .adv-icon {
      width: 40px;
      height: 40px;
      margin-bottom: 20px;
    }
    .adv-title {
      font-size: 24px;
      margin-bottom: 12px;
    }

    /* 业务交错 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 0 0 45%;
      border-radius: var(--radius-md);
      overflow: hidden;
    }
    .service-img img {
      width: 100%;
      height: 320px;
      object-fit: cover;
    }
    .service-text {
      flex: 1;
    }
    .service-text h3 {
      color: var(--sandstone-gold);
      font-size: 28px;
      margin-bottom: 16px;
    }

    /* 指标 */
    .metrics {
      background: var(--deep-stone);
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 30px;
      text-align: center;
    }
    .metric-number {
      font-family: var(--font-mono);
      font-size: 42px;
      color: var(--sandstone-gold);
      font-weight: 700;
    }
    .metric-label {
      color: rgba(247,245,240,0.7);
      font-size: 14px;
    }

    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 28px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid var(--border-light);
    }
    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .case-img {
      height: 200px;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.5s;
    }
    .case-card:hover .case-img img {
      transform: scale(1.05);
    }
    .case-info {
      padding: 24px;
    }
    .case-tag {
      background: rgba(200,169,110,0.1);
      color: var(--sandstone-gold);
      font-size: 12px;
      padding: 2px 10px;
      border-radius: 4px;
      display: inline-block;
      margin-bottom: 10px;
    }

    /* 流程时间线 */
    .timeline {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }
    .timeline-step {
      display: flex;
      gap: 30px;
      align-items: baseline;
    }
    .timeline-marker {
      display: flex;
      flex-direction: column;
      align-items: center;
    }
    .dot {
      width: 16px;
      height: 16px;
      background: var(--sandstone-gold);
      border-radius: 50%;
    }
    .line {
      width: 2px;
      height: 50px;
      background: repeating-linear-gradient(to bottom, var(--sandstone-gold) 0 4px, transparent 4px 10px);
    }
    .timeline-content {
      background: white;
      padding: 24px;
      border-radius: var(--radius-md);
      flex: 1;
      box-shadow: var(--shadow-sm);
    }

    /* FAQ */
    details {
      background: white;
      padding: 20px 24px;
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      border: 1px solid var(--border-light);
      transition: var(--transition);
    }
    details[open] {
      border-left: 4px solid var(--sandstone-gold);
    }
    summary {
      font-weight: 500;
      cursor: pointer;
      list-style: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    summary::after {
      content: "+";
      font-size: 22px;
      color: var(--sandstone-gold);
      transition: transform 0.3s;
    }
    details[open] summary::after {
      content: "−";
      transform: rotate(180deg);
    }

    /* CTA */
    .contact-block {
      background: var(--sandstone-gold);
      display: flex;
      gap: 50px;
      align-items: center;
    }
    .contact-left h2 {
      color: var(--deep-stone);
    }
    .contact-form input {
      width: 100%;
      padding: 14px;
      margin-bottom: 16px;
      border: 1px solid #D4C5A2;
      border-radius: var(--radius-sm);
      background: white;
      font-size: 16px;
    }

    .footer {
      background: var(--deep-stone);
      color: rgba(247,245,240,0.6);
      padding: 40px 0;
    }
    .footer-grid {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 20px;
    }
    .footer-links a {
      color: rgba(247,245,240,0.6);
      margin-left: 24px;
      transition: color var(--transition);
    }
    .footer-links a:hover {
      color: var(--sandstone-gold);
    }

    @media (max-width: 1024px) {
      .hero-content {
        flex-direction: column;
        text-align: center;
      }
      .hero-text, .hero-image {
        flex: auto;
        width: 100%;
      }
      .metrics-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 768px) {
      .container, .nav-container {
        padding: 0 20px;
      }
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      section {
        padding: 60px 0;
      }
      .advantages-grid, .cases-grid {
        grid-template-columns: 1fr;
      }
      .service-row, .service-row.reverse {
        flex-direction: column;
      }
      .hero h1 {
        font-size: 32px;
      }
      .section-title {
        font-size: 26px;
      }
    }