/* roulang page: index */
/* 设计变量与基础重置 */
    :root {
      --deep-ocean: #0B3D5C;
      --whale-teal: #1A8C8C;
      --coral-warm: #F4A261;
      --coral-hover: #E08C3E;
      --bg-mist: #F7F9FB;
      --dark-bg: #082B40;
      --text-primary: #1A2B3C;
      --text-secondary: #4A5B6C;
      --text-on-dark: #FFFFFF;
      --border-light: #E2E8F0;
      --card-shadow: 0 4px 20px rgba(11,61,92,0.06);
      --card-shadow-hover: 0 8px 30px rgba(11,61,92,0.12);
      --radius-lg: 12px;
      --radius-sm: 8px;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', sans-serif;
      --font-number: 'DIN Alternate', 'PingFang SC', sans-serif;
      --transition: 0.3s ease;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
      scroll-padding-top: 80px;
    }

    body {
      font-family: var(--font-body);
      font-size: 16px;
      line-height: 1.75;
      color: var(--text-primary);
      background-color: var(--bg-mist);
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    h1, h2, h3, h4 {
      font-family: var(--font-heading);
      font-weight: 600;
      line-height: 1.3;
    }

    h1 {
      font-size: 48px;
      font-weight: 700;
      color: #FFFFFF;
    }

    h2 {
      font-size: 36px;
      color: var(--deep-ocean);
      margin-bottom: 16px;
    }

    h3 {
      font-size: 22px;
      color: var(--text-primary);
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      font-weight: 600;
      transition: var(--transition);
      display: inline-block;
      text-align: center;
    }

    /* 玻璃沉浸导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(255,255,255,0.75);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.3);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      transition: background 0.3s, box-shadow 0.3s;
    }

    .site-header.scrolled {
      background: rgba(255,255,255,0.95);
      box-shadow: 0 4px 20px rgba(0,0,0,0.08);
      backdrop-filter: blur(10px);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-family: var(--font-heading);
      font-size: 22px;
      font-weight: 700;
      color: var(--deep-ocean);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo i {
      font-size: 28px;
      color: var(--deep-ocean);
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-link {
      color: var(--text-primary);
      font-weight: 500;
      position: relative;
      padding: 4px 0;
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--whale-teal);
      transition: width 0.2s;
    }

    .nav-link:hover {
      color: var(--whale-teal);
    }

    .nav-link:hover::after {
      width: 100%;
    }

    .btn-cta-sm {
      background: var(--coral-warm);
      color: white;
      padding: 8px 20px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 14px;
      border: none;
    }

    .btn-cta-sm:hover {
      background: var(--coral-hover);
      transform: scale(1.02);
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--deep-ocean);
    }

    /* Hero 首屏 */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, #0B3D5C, #082B40);
      position: relative;
      overflow: hidden;
      padding-top: 80px;
    }

    .hero-bg-img {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.3;
      z-index: 0;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
      color: white;
    }

    .hero h1 {
      margin-bottom: 24px;
      letter-spacing: 1px;
    }

    .hero-subtitle {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 40px;
      max-width: 600px;
    }

    .hero-actions {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--coral-warm);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-size: 16px;
      border: none;
      box-shadow: 0 4px 12px rgba(244,162,97,0.3);
    }

    .btn-primary:hover {
      background: var(--coral-hover);
      transform: scale(1.03);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--whale-teal);
      color: var(--whale-teal);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
    }

    .btn-outline:hover {
      background: var(--whale-teal);
      color: white;
    }

    /* 通用板块 */
    .section {
      padding: 100px 0;
    }

    .section-header {
      text-align: center;
      margin-bottom: 60px;
    }

    .section-header p {
      color: var(--text-secondary);
      max-width: 600px;
      margin: 0 auto;
    }

    /* 核心优势 */
    .advantages-grid {
      display: flex;
      gap: 40px;
      justify-content: center;
    }

    .adv-item {
      text-align: center;
      flex: 1;
    }

    .adv-icon {
      width: 80px;
      height: 80px;
      background: var(--whale-teal);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: white;
      font-size: 32px;
    }

    /* 功能矩阵 */
    .matrix-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .service-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      box-shadow: var(--card-shadow);
      border: 1px solid var(--border-light);
      transition: var(--transition);
    }

    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--card-shadow-hover);
    }

    .card-img {
      height: 160px;
      border-radius: 12px;
      overflow: hidden;
      margin-bottom: 24px;
    }

    .card-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    /* 场景叙事 */
    .scene-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }

    .scene-row.reverse {
      flex-direction: row-reverse;
    }

    .scene-img {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: 0 8px 30px rgba(0,0,0,0.1);
    }

    .scene-text {
      flex: 1;
    }

    /* 数据背书 */
    .stats-wall {
      display: flex;
      justify-content: space-around;
      text-align: center;
      background: white;
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: var(--card-shadow);
    }

    .stat-number {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 700;
      color: var(--coral-warm);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: white;
      border-bottom: 1px solid var(--border-light);
    }

    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 16px;
      font-size: 18px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--text-primary);
    }

    .faq-answer {
      padding: 0 16px 20px;
      color: var(--text-secondary);
      display: none;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--dark-bg);
      text-align: center;
      padding: 100px 24px;
    }

    /* 页脚 */
    .site-footer {
      background: var(--dark-bg);
      color: #A0B4C4;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }

    @media (max-width: 1024px) {
      h1 { font-size: 40px; }
      .matrix-grid { grid-template-columns: repeat(2,1fr); }
      .scene-row { flex-direction: column; }
      .scene-row.reverse { flex-direction: column; }
    }

    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: block; }
      .advantages-grid { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .stats-wall { flex-wrap: wrap; gap: 20px; }
    }