/* roulang page: index */
/* ----- CSS 变量与全局重置 ----- */
    :root {
      --primary: #0B1A2F;
      --accent-1: #00C6B7;
      --accent-2: #F5A623;
      --bg: #FAFBFD;
      --text-primary: #0B1A2F;
      --text-body: #2C3E50;
      --text-muted: #5D6D7E;
      --white: #FFFFFF;
      --border-light: #E9EDF2;
      --card-shadow: 0 4px 20px rgba(11, 26, 47, 0.04);
      --card-shadow-hover: 0 12px 32px rgba(11, 26, 47, 0.08);
      --radius-card: 20px;
      --radius-btn: 50px;
      --radius-sm: 12px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --font-mono: "Inter", "SF Mono", "JetBrains Mono", monospace;
      --transition: 0.25s ease;
      --max-width: 1280px;
      --nav-height: 72px;
    }

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

    html {
      scroll-behavior: smooth;
      scroll-padding-top: var(--nav-height);
    }

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

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }

    button, input {
      font-family: inherit;
      outline: none;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* ----- 导航 (极简高端文字导航) ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      z-index: 100;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
      letter-spacing: -0.3px;
    }

    .nav-links {
      display: flex;
      gap: 40px;
      align-items: center;
    }

    .nav-links a {
      font-size: 15px;
      color: var(--text-body);
      position: relative;
      padding: 8px 0;
      font-weight: 500;
      transition: color var(--transition);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 3px;
      background: var(--accent-1);
      border-radius: 2px;
      transition: width 0.2s ease;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-1);
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 24px;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 4px;
    }

    .hamburger span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: 0.3s;
    }

    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        right: 0;
        width: 70%;
        max-width: 320px;
        height: 100vh;
        background: rgba(11, 26, 47, 0.96);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        gap: 32px;
        transform: translateX(100%);
        transition: transform 0.35s ease;
        z-index: 200;
      }
      .nav-links.open {
        transform: translateX(0);
      }
      .nav-links a {
        color: white;
        font-size: 20px;
        text-align: center;
      }
      .nav-links a::after {
        background: var(--accent-1);
      }
      .hamburger {
        display: flex;
        z-index: 210;
      }
    }

    /* ----- 板块通用 ----- */
    .section {
      padding: 90px 0;
    }

    @media (max-width: 640px) {
      .section {
        padding: 60px 0;
      }
    }

    .section-title {
      font-size: 34px;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 16px;
      position: relative;
      display: inline-block;
    }

    .section-title::after {
      content: '';
      display: block;
      width: 48px;
      height: 4px;
      background: var(--accent-1);
      margin-top: 8px;
      border-radius: 2px;
    }

    .section-sub {
      color: var(--text-muted);
      margin-bottom: 48px;
      font-size: 16px;
    }

    /* ----- 按钮系统 ----- */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      transition: all 0.2s ease;
      cursor: pointer;
      border: 2px solid transparent;
    }

    .btn-primary {
      background: var(--accent-1);
      color: white;
      border-color: var(--accent-1);
    }

    .btn-primary:hover {
      background: #00A99C;
      border-color: #00A99C;
      box-shadow: 0 8px 20px rgba(0, 198, 183, 0.3);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }

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

    /* ----- Hero 首屏 ----- */
    .hero {
      padding-top: calc(var(--nav-height) + 60px);
      padding-bottom: 80px;
      background: linear-gradient(135deg, #0B1A2F 0%, #05101E 100%);
      position: relative;
      overflow: hidden;
    }

    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.12;
      mix-blend-mode: overlay;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
      z-index: 2;
    }

    .hero-left {
      flex: 1.2;
    }

    .hero-left h1 {
      font-size: 52px;
      font-weight: 700;
      color: white;
      line-height: 1.2;
      letter-spacing: -0.02em;
      margin-bottom: 24px;
    }

    .hero-left .subtitle {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      margin-bottom: 16px;
    }

    .hero-left p {
      color: rgba(255,255,255,0.7);
      margin-bottom: 32px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-right {
      flex: 0.9;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .metric-badge {
      background: rgba(11, 26, 47, 0.7);
      backdrop-filter: blur(8px);
      border-radius: 20px;
      padding: 20px 24px;
      border: 1px solid rgba(255,255,255,0.1);
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .metric-number {
      font-family: var(--font-mono);
      font-size: 36px;
      font-weight: 700;
      color: var(--accent-1);
    }

    .metric-label {
      color: rgba(255,255,255,0.8);
      font-size: 14px;
    }

    @media (max-width: 900px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-left h1 {
        font-size: 36px;
      }
      .hero-right {
        width: 100%;
      }
    }

    /* ----- 卡片通用 ----- */
    .card {
      background: white;
      border-radius: var(--radius-card);
      border: 1px solid var(--border-light);
      box-shadow: var(--card-shadow);
      padding: 32px;
      transition: all var(--transition);
    }

    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--card-shadow-hover);
      border-color: var(--accent-1);
    }

    /* ----- 核心能力指标 ----- */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .metric-card {
      text-align: center;
    }

    .metric-card .big-number {
      font-family: var(--font-mono);
      font-size: 40px;
      font-weight: 700;
      color: var(--accent-1);
    }

    @media (max-width: 900px) {
      .metrics-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 500px) {
      .metrics-grid {
        grid-template-columns: 1fr;
      }
    }

    /* ----- 服务矩阵 ----- */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card img {
      width: 100%;
      height: 140px;
      object-fit: cover;
      border-radius: 12px;
      margin-bottom: 20px;
    }

    .tag {
      background: #EEF2F6;
      color: var(--text-body);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      display: inline-block;
      margin-right: 8px;
    }

    @media (max-width: 1024px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }

    /* ----- 对比表 ----- */
    .compare-row {
      display: flex;
      gap: 24px;
      margin-top: 24px;
    }

    .compare-card {
      flex: 1;
      padding: 28px;
      border-radius: var(--radius-card);
    }

    .compare-old {
      background: #F2F4F7;
      color: var(--text-muted);
    }

    .compare-new {
      background: white;
      border: 2px solid var(--accent-1);
    }

    .strike {
      text-decoration: line-through;
      color: #999;
    }

    .highlight-badge {
      background: var(--accent-2);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
      margin-left: 10px;
    }

    @media (max-width: 700px) {
      .compare-row {
        flex-direction: column;
      }
    }

    /* ----- FAQ 手风琴 ----- */
    .faq-item {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      overflow: hidden;
    }

    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: transparent;
      border: none;
      width: 100%;
      text-align: left;
      font-size: 18px;
      color: var(--text-primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding: 0 24px;
      color: var(--text-muted);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* ----- CTA ----- */
    .cta-section {
      background: linear-gradient(135deg, #0B1A2F, #05101E);
      text-align: center;
      color: white;
    }

    .cta-form {
      display: flex;
      justify-content: center;
      gap: 12px;
      margin-top: 28px;
      flex-wrap: wrap;
    }

    .cta-input {
      padding: 14px 24px;
      border-radius: 50px;
      border: none;
      min-width: 260px;
    }

    .trust-badges {
      display: flex;
      justify-content: center;
      gap: 32px;
      margin-top: 24px;
      color: rgba(255,255,255,0.7);
    }

    /* ----- 页脚 ----- */
    .footer {
      background: #0B1A2F;
      color: #5D6D7E;
      padding: 32px 0;
    }

    .footer-grid {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 20px;
    }