/* roulang page: index */
:root {
      --primary: #1E2A3A;
      --primary-hover: #2C3A4F;
      --accent: #C8A96E;
      --accent-light: rgba(200, 169, 110, 0.15);
      --bg-page: #F7F8FA;
      --bg-white: #FFFFFF;
      --bg-light: #F0F2F5;
      --bg-compare-dark: #E9EBEE;
      --text-heading: #1A1A1A;
      --text-body: #4A4A4A;
      --text-muted: #7A7A7A;
      --text-footer: #B0B8C1;
      --border-light: #E5E7EB;
      --border-input: #D1D5DB;
      --success: #2D5A3B;
      --negative: #B55A5A;
      --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.06);
      --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.10);
      --radius-card: 8px;
      --radius-btn: 6px;
      --radius-badge: 4px;
      --font-sans: '思源黑体', 'Source Han Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --font-number: 'Inter', 'Roboto', var(--font-sans);
      --transition: 0.2s ease;
    }

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

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.7;
      font-weight: 400;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input, select {
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航栏 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--bg-white);
      border-bottom: 1px solid var(--border-light);
      height: 72px;
      display: flex;
      align-items: center;
    }

    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 6px;
      letter-spacing: 0.5px;
    }

    .logo-dot {
      display: inline-block;
      width: 10px;
      height: 10px;
      background: var(--accent);
      transform: rotate(45deg);
      margin-right: 4px;
    }

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

    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-body);
      position: relative;
      padding: 4px 0;
    }

    .nav-link.active,
    .nav-link:hover {
      color: var(--primary);
    }

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent);
      border-radius: 2px;
    }

    .burger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 8px;
    }

    .burger span {
      display: block;
      width: 22px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      height: calc(100vh - 72px);
      background: rgba(30, 42, 58, 0.97);
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 40px;
      z-index: 40;
    }

    .mobile-menu a {
      font-size: 22px;
      color: white;
      font-weight: 500;
    }

    .mobile-menu.open {
      display: flex;
    }

    /* 区块通用 */
    .section {
      padding: 100px 0;
    }

    .section-title {
      font-size: 32px;
      font-weight: 700;
      color: var(--text-heading);
      margin-bottom: 16px;
      line-height: 1.3;
    }

    .section-desc {
      font-size: 18px;
      color: var(--text-muted);
      max-width: 680px;
      margin-bottom: 48px;
    }

    /* 首屏 */
    .hero {
      background-color: var(--bg-page);
      position: relative;
      overflow: hidden;
      padding: 80px 0;
      min-height: 600px;
      display: flex;
      align-items: center;
    }

    .hero-bg {
      position: absolute;
      right: 0;
      top: 0;
      width: 55%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.25;
      mask-image: radial-gradient(circle at center, black 20%, transparent 80%);
      -webkit-mask-image: radial-gradient(circle at center, black 20%, transparent 80%);
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 650px;
    }

    .hero h1 {
      font-size: 44px;
      font-weight: 700;
      color: var(--text-heading);
      line-height: 1.2;
      margin-bottom: 20px;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-body);
      margin-bottom: 32px;
    }

    .badge-row {
      display: flex;
      gap: 24px;
      margin-bottom: 36px;
      flex-wrap: wrap;
    }

    .badge-item {
      font-size: 14px;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .badge-num {
      font-family: var(--font-number);
      font-weight: 700;
      font-size: 20px;
      color: var(--accent);
    }

    .badge-sep {
      width: 1px;
      height: 18px;
      background: var(--border-light);
    }

    .btn-group {
      display: flex;
      gap: 20px;
      align-items: center;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      border: none;
      cursor: pointer;
      transition: var(--transition);
      display: inline-block;
    }

    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 6px 18px rgba(30, 42, 58, 0.2);
    }

    .btn-ghost {
      background: transparent;
      color: var(--primary);
      border: 1.5px solid var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
    }

    .btn-ghost:hover {
      background: rgba(30, 42, 58, 0.06);
    }

    .text-link {
      color: var(--accent);
      font-weight: 500;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: var(--transition);
    }

    .text-link:hover {
      text-decoration: underline;
      color: var(--accent);
    }

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

    .metric-card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      text-align: center;
      box-shadow: var(--shadow-card);
    }

    .metric-number {
      font-family: var(--font-number);
      font-weight: 700;
      font-size: 38px;
      color: var(--accent);
      font-feature-settings: "tnum";
      line-height: 1.2;
    }

    .metric-unit {
      font-size: 16px;
      font-weight: 600;
      color: var(--primary);
      margin-left: 2px;
    }

    .metric-label {
      font-size: 14px;
      color: var(--text-muted);
      margin-top: 8px;
    }

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

    .service-card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 32px 28px;
      box-shadow: var(--shadow-card);
      transition: transform 0.25s, box-shadow 0.25s;
    }

    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .service-icon {
      width: 48px;
      height: 48px;
      margin-bottom: 20px;
      color: var(--primary);
      opacity: 0.8;
    }

    .service-card h3 {
      font-size: 22px;
      font-weight: 600;
      color: var(--text-heading);
      margin-bottom: 12px;
    }

    .service-desc {
      font-size: 15px;
      color: var(--text-muted);
      margin-bottom: 18px;
    }

    /* 对比区 */
    .compare-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      align-items: start;
    }

    .compare-card {
      border-radius: var(--radius-card);
      padding: 32px;
    }

    .compare-left {
      background: var(--bg-compare-dark);
    }

    .compare-right {
      background: var(--bg-white);
      border-left: 4px solid var(--primary);
      box-shadow: var(--shadow-card);
    }

    .compare-title {
      font-size: 22px;
      font-weight: 700;
      margin-bottom: 24px;
    }

    .compare-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 14px 0;
      border-bottom: 1px solid var(--border-light);
      font-size: 15px;
    }

    .mark-negative {
      color: var(--negative);
      font-weight: 600;
    }

    .mark-positive {
      color: var(--success);
      font-weight: 600;
    }

    /* FAQ */
    .faq-list {
      max-width: 720px;
      margin: 0 auto;
    }

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

    .faq-question {
      width: 100%;
      text-align: left;
      background: none;
      border: none;
      padding: 20px 0;
      font-size: 18px;
      font-weight: 600;
      color: var(--text-heading);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: var(--transition);
    }

    .faq-question:hover {
      color: var(--primary);
    }

    .faq-icon {
      font-size: 22px;
      font-weight: 400;
      transition: transform 0.3s;
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      font-size: 16px;
      color: var(--text-body);
      padding-left: 12px;
      border-left: 3px solid transparent;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 0 20px 12px;
      border-left-color: var(--accent);
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* 表单 */
    .contact-section {
      background: var(--bg-light);
    }

    .form-row {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      align-items: center;
    }

    .form-input {
      flex: 1;
      min-width: 180px;
      padding: 12px 16px;
      border: 1px solid var(--border-input);
      border-radius: var(--radius-btn);
      background: white;
      font-size: 15px;
      transition: var(--transition);
    }

    .form-input:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(30, 42, 58, 0.1);
    }

    .btn-submit {
      background: var(--primary);
      color: white;
      padding: 13px 32px;
      border: none;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition);
      white-space: nowrap;
    }

    .btn-submit:hover {
      background: var(--primary-hover);
    }

    /* 页脚 */
    .footer {
      background: var(--primary);
      color: var(--text-footer);
      padding: 60px 0 30px;
      border-top: 2px solid var(--accent);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr;
      gap: 40px;
    }

    .footer-logo {
      font-size: 20px;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }

    .footer a {
      color: var(--text-footer);
    }

    .footer a:hover {
      color: var(--accent);
    }

    .copyright {
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid rgba(255,255,255,0.1);
      font-size: 14px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .metrics-grid { grid-template-columns: repeat(2, 1fr); }
      .services-grid { grid-template-columns: repeat(2, 1fr); }
      .compare-wrapper { grid-template-columns: 1fr; }
      .hero-bg { width: 100%; opacity: 0.18; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .burger { display: flex; }
      .section { padding: 70px 0; }
      .hero h1 { font-size: 32px; }
      .metrics-grid { grid-template-columns: 1fr 1fr; }
      .services-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
    }

    @media (max-width: 520px) {
      .hero h1 { font-size: 28px; }
      .badge-row { gap: 12px; }
      .form-row { flex-direction: column; }
    }