/* roulang page: index */
/* ---------- 设计系统变量 ---------- */
    :root {
      --ice-blue: #0A6E7D;
      --penguin-orange: #F47B20;
      --glacier-gray: #4A5B5E;
      --deep-charcoal: #1E1E24;
      --frost-white: #FAFCFD;
      --soft-ice: #F4F9FD;
      --border-light: #E8F0F2;
      --shadow-card: 0 4px 20px rgba(10, 110, 125, 0.08);
      --shadow-hover: 0 14px 30px rgba(10, 110, 125, 0.15);
      --radius-card: 14px;
      --radius-btn: 8px;
      --transition: all 0.28s ease;
      --content-width: 1280px;
      --nav-height: 72px;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--frost-white);
      color: var(--glacier-gray);
      line-height: 1.6;
      font-weight: 400;
      overflow-x: hidden;
    }
    .container {
      max-width: var(--content-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    h1, h2, h3, h4 {
      font-weight: 600;
    }
    .section {
      padding: 90px 0;
    }
    /* ---------- 导航 ---------- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(250, 252, 253, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 var(--border-light);
      z-index: 999;
      display: flex;
      align-items: center;
      transition: var(--transition);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 28px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 22px;
      font-weight: 700;
      color: var(--ice-blue);
      white-space: nowrap;
    }
    .logo svg {
      width: 28px;
      height: 28px;
      fill: var(--penguin-orange);
    }
    .nav-list {
      display: flex;
      list-style: none;
      gap: 28px;
      align-items: center;
    }
    .nav-list a {
      font-size: 16px;
      font-weight: 500;
      color: var(--glacier-gray);
      transition: var(--transition);
      position: relative;
      padding-bottom: 6px;
    }
    .nav-list a:hover {
      color: var(--ice-blue);
    }
    .nav-list a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--ice-blue);
      transition: width 0.25s ease;
    }
    .nav-list a:hover::after {
      width: 100%;
    }
    .btn-cta {
      background: var(--penguin-orange);
      color: white !important;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(244, 123, 32, 0.3);
      margin-left: 8px;
    }
    .btn-cta:hover {
      background: #E06A10;
      transform: scale(1.04);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      flex-direction: column;
      gap: 6px;
    }
    .menu-toggle span {
      width: 26px;
      height: 3px;
      background: var(--ice-blue);
      border-radius: 4px;
      transition: 0.2s;
    }
    /* 移动端菜单 */
    @media (max-width: 960px) {
      .nav-list {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: white;
        flex-direction: column;
        padding: 100px 32px;
        gap: 28px;
        box-shadow: -8px 0 24px rgba(0,0,0,0.08);
        transition: right 0.35s;
        z-index: 1000;
      }
      .nav-list.active {
        right: 0;
      }
      .menu-toggle {
        display: flex;
        z-index: 1100;
      }
      .btn-cta {
        margin-left: 0;
        width: fit-content;
      }
    }
    /* 遮罩 */
    .menu-overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.4);
      z-index: 999;
      display: none;
    }
    .menu-overlay.show {
      display: block;
    }

    /* ------- HERO ------- */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(180deg, #FAFCFD 0%, #f0f6f8 100%);
      padding-top: var(--nav-height);
      position: relative;
      overflow: hidden;
    }
    .hero::after {
      content: '';
      position: absolute;
      right: 0;
      bottom: 0;
      width: 50%;
      height: 100%;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200" opacity="0.05"><path d="M75 60 Q85 45 105 55 Q125 65 115 80 Q95 90 80 73 Z" fill="%230A6E7D"/><circle cx="140" cy="120" r="18" fill="%230A6E7D"/></svg>') no-repeat center/contain;
      pointer-events: none;
      transform: scaleX(-1);
    }
    .hero-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      flex-wrap: wrap;
    }
    .hero-text {
      flex: 1 1 480px;
    }
    .hero-text h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.15;
      color: var(--deep-charcoal);
      margin-bottom: 18px;
    }
    .hero-text p {
      font-size: 18px;
      color: var(--glacier-gray);
      margin-bottom: 32px;
      max-width: 520px;
    }
    .btn-group {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--penguin-orange);
      border: none;
      color: white;
      padding: 14px 34px;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-primary:hover {
      background: #D65F0E;
      transform: scale(1.03);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--ice-blue);
      color: var(--ice-blue);
      padding: 14px 30px;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: var(--transition);
    }
    .btn-secondary:hover {
      background: var(--ice-blue);
      color: white;
    }
    .hero-image {
      flex: 1 1 460px;
      position: relative;
      z-index: 2;
    }
    .hero-image img {
      border-radius: 26px;
      box-shadow: 0 20px 35px rgba(0,0,0,0.12);
      background-color: #ddd;
      aspect-ratio: 4/3;
      object-fit: cover;
    }

    /* 卡片通用 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 28px;
    }
    .adv-card {
      background: white;
      padding: 32px 22px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      text-align: center;
      transition: var(--transition);
    }
    .adv-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-7px);
    }
    .adv-card img {
      width: 64px;
      height: 64px;
      object-fit: contain;
      margin: 0 auto 20px;
    }
    .adv-card h3 {
      color: var(--ice-blue);
      margin-bottom: 8px;
    }
    
    .bg-ice { background: #F4F9FD; }
    
    .service-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 70px;
      background: white;
      border-radius: 18px;
      padding: 24px;
      box-shadow: 0 4px 15px rgba(0,0,0,0.03);
    }
    .service-img, .service-text {
      flex: 1;
    }
    .service-img img {
      border-radius: 18px;
      height: 260px;
      object-fit: cover;
      width: 100%;
    }
    .service-text h3 { font-size: 24px; color: var(--deep-charcoal); }
    .link-underline {
      color: var(--ice-blue);
      font-weight: 600;
      display: inline-block;
      margin-top: 12px;
      position: relative;
    }
    .link-underline::after {
      content: '';
      display: block;
      width: 0;
      height: 2px;
      background: var(--ice-blue);
      transition: 0.25s;
    }
    .link-underline:hover::after { width: 100%; }

    .stats { display: flex; justify-content: space-around; flex-wrap: wrap; margin: 30px 0; }
    .stat-item h2 { font-size: 48px; color: var(--penguin-orange); }
    .case-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 24px; }
    .case-card {
      border: 2px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 20px;
      transition: var(--transition);
    }
    .case-card:hover {
      border-color: var(--ice-blue);
      background: #f0f9fb;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 6px;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      align-items: center;
      gap: 14px;
      font-weight: 600;
      font-size: 18px;
      padding: 18px 10px;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: #F4F9FD;
      padding-left: 48px;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 16px 36px 16px 48px;
    }
    .cta-block {
      background: linear-gradient(135deg, #0A6E7D, #034450);
      border-radius: 32px;
      text-align: center;
      padding: 70px 24px;
      color: white;
    }
    .footer {
      background: #1E1E24;
      color: #B0B8BA;
      padding: 60px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    @media (max-width: 768px) {
      .card-grid, .case-grid, .footer-grid { grid-template-columns: 1fr; }
      .hero-container { flex-direction: column; text-align: center; }
      .hero-text h1 { font-size: 32px; }
      .service-row { flex-direction: column; }
      .stats { gap: 30px; }
    }