/* roulang page: index */
/* ----- 设计变量 & 基础重置 ----- */
    :root {
      --deep-blue: #1A2332;
      --gold-copper: #C5A059;
      --bronze: #9C7A3C;
      --warm-white: #F9F7F4;
      --ink-gray: #2C3E50;
      --stone-gray: #7F8C8D;
      --border-light: #E0DCD5;
      --tag-bg: #EDEAE6;
      --white: #FFFFFF;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.08);
      --radius-card: 8px;
      --radius-btn: 4px;
      --radius-pill: 40px;
      --transition: 0.3s ease;
      --font-stack: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "WenQuanYi Micro Hei", sans-serif;
      --section-gap: 100px;
      --content-width: 1200px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-stack);
      background-color: var(--warm-white);
      color: var(--ink-gray);
      line-height: 1.8;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: var(--content-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    h2 {
      font-size: 2.25rem;
      font-weight: 600;
      line-height: 1.3;
      color: var(--deep-blue);
      margin-bottom: 1.5rem;
      position: relative;
      display: inline-block;
    }
    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 60px;
      height: 4px;
      background-color: var(--gold-copper);
      border-radius: 2px;
    }
    h3 {
      font-size: 1.25rem;
      font-weight: 600;
      line-height: 1.4;
      color: var(--ink-gray);
    }
    /* ----- 导航栏：分段标签风格 ----- */
    .site-header {
      background-color: var(--white);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      position: sticky;
      top: 0;
      z-index: 100;
      padding: 16px 0;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--deep-blue);
      letter-spacing: 1px;
    }
    .logo-icon {
      width: 36px;
      height: 36px;
      background-color: var(--gold-copper);
      border-radius: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: bold;
      font-size: 1.2rem;
    }
    .nav-tags {
      display: flex;
      align-items: center;
      background-color: var(--tag-bg);
      border-radius: var(--radius-pill);
      padding: 4px;
      flex-wrap: wrap;
      gap: 2px;
    }
    .nav-tag {
      padding: 10px 24px;
      border-radius: 36px;
      color: var(--stone-gray);
      font-weight: 500;
      transition: var(--transition);
      white-space: nowrap;
    }
    .nav-tag:hover {
      color: var(--ink-gray);
      background-color: rgba(197,160,89,0.1);
    }
    .cta-btn {
      background-color: var(--gold-copper);
      color: white;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      transition: var(--transition);
      white-space: nowrap;
      border: none;
      cursor: pointer;
    }
    .cta-btn:hover {
      background-color: var(--bronze);
    }
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--deep-blue);
      cursor: pointer;
    }
    /* ----- Hero 首屏 ----- */
    .hero {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      min-height: 85vh;
      color: white;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(180deg, rgba(26,35,50,0.7) 0%, rgba(26,35,50,0.85) 100%);
      z-index: 1;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      padding: 0 24px;
    }
    .hero h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      color: white;
      margin-bottom: 1.5rem;
    }
    .hero .subtitle {
      font-size: 1.25rem;
      color: rgba(255,255,255,0.9);
      margin-bottom: 2.5rem;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .btn-primary {
      background-color: var(--gold-copper);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      border: none;
      display: inline-block;
    }
    .btn-primary:hover {
      background-color: var(--bronze);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--gold-copper);
      color: var(--gold-copper);
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      display: inline-block;
    }
    .btn-secondary:hover {
      background-color: var(--gold-copper);
      color: white;
    }
    /* 通用板块 */
    .section {
      padding: var(--section-gap) 0;
    }
    .section-header {
      margin-bottom: 3rem;
    }
    /* 集团概况 */
    .about-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .about-text p {
      margin-bottom: 1.5em;
      color: var(--ink-gray);
    }
    .about-image img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
    }
    /* 核心优势 2x3 网格 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .advantage-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .advantage-icon {
      font-size: 2rem;
      color: var(--gold-copper);
      margin-bottom: 16px;
    }
    /* Tab 服务体系 */
    .tabs-container {
      display: flex;
      justify-content: center;
      gap: 10px;
      margin-bottom: 40px;
      background: var(--tag-bg);
      border-radius: var(--radius-pill);
      padding: 4px;
      width: fit-content;
      margin-left: auto;
      margin-right: auto;
      flex-wrap: wrap;
    }
    .tab-btn {
      padding: 12px 28px;
      border-radius: 36px;
      background: transparent;
      border: none;
      color: var(--stone-gray);
      font-weight: 500;
      cursor: pointer;
      transition: var(--transition);
    }
    .tab-btn.active {
      background: var(--gold-copper);
      color: white;
      font-weight: 600;
    }
    .tab-pane {
      display: none;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .tab-pane.active {
      display: grid;
    }
    .tab-image img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
    }
    /* 成功案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .case-card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      transition: var(--transition);
      border: 1px solid var(--border-light);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .case-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .case-info {
      padding: 20px;
    }
    /* FAQ 手风琴 */
    .faq-item {
      background: var(--white);
      border-bottom: 1px solid var(--tag-bg);
      margin-bottom: 8px;
      border-radius: 6px;
    }
    .faq-question {
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--ink-gray);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      padding: 0 20px;
      color: var(--stone-gray);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }
    /* 联系表单 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 50px;
    }
    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 14px;
      margin-bottom: 16px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-btn);
      background: var(--white);
      transition: var(--transition);
    }
    .contact-form input:focus, .contact-form textarea:focus {
      border-color: var(--gold-copper);
      box-shadow: 0 0 0 3px rgba(197,160,89,0.1);
      outline: none;
    }
    .footer {
      background: var(--deep-blue);
      color: rgba(255,255,255,0.8);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }
    .footer a {
      color: rgba(255,255,255,0.7);
    }
    .footer a:hover {
      color: var(--gold-copper);
    }
    @media (max-width: 768px) {
      .nav-tags { display: none; }
      .mobile-menu-toggle { display: block; }
      .about-grid, .tab-pane.active, .contact-grid { grid-template-columns: 1fr; }
      .advantages-grid, .cases-grid { grid-template-columns: 1fr 1fr; }
      .hero h1 { font-size: 2.2rem; }
    }
    @media (max-width: 480px) {
      .advantages-grid, .cases-grid { grid-template-columns: 1fr; }
      .hero-buttons .btn-primary, .hero-buttons .btn-secondary { width: 100%; }
      .footer-grid { grid-template-columns: 1fr; }
    }