/* roulang page: index */
:root {
      --primary: #1E252B;
      --accent: #0D828A;
      --cta: #F36A22;
      --cta-hover: #D85614;
      --bg-light: #F8FAFB;
      --bg-white: #FFFFFF;
      --bg-dark: #12181F;
      --text-main: #2D3748;
      --text-muted: #64748B;
      --border-color: #E2E8F0;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 4px 20px -2px rgba(13, 130, 138, 0.08);
      --shadow-lg: 0 10px 25px -5px rgba(30, 37, 43, 0.12);
      --radius: 8px;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: system-ui, -apple-system, "PingFang SC", "Lantinghei SC", "Microsoft YaHei", sans-serif;
      line-height: 1.75;
      color: var(--text-main);
      background-color: var(--bg-light);
      -webkit-font-smoothing: antialiased;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: all 0.25s ease;
    }

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

    .container {
      width: 100%;
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.25rem;
      padding-right: 1.25rem;
    }

    /* 顶部通栏 */
    .top-bar {
      background-color: #151A1E;
      color: #94A3B8;
      font-size: 0.875rem;
      border-bottom: 1px solid #232B32;
    }
    .top-bar-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0.5rem 0;
      flex-wrap: wrap;
      gap: 0.5rem;
    }
    .top-bar-item {
      display: inline-flex;
      align-items: center;
      gap: 0.35rem;
    }

    /* 导航栏 */
    .header-nav {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.96);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 72px;
    }
    .logo-box {
      display: flex;
      align-items: center;
      gap: 0.75rem;
    }
    .logo-badge {
      width: 40px;
      height: 40px;
      background: var(--accent);
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius);
      font-weight: 700;
      font-size: 1.25rem;
      box-shadow: 0 2px 6px rgba(13, 130, 138, 0.3);
    }
    .logo-text {
      font-size: 1.35rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.02em;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 1.75rem;
      list-style: none;
    }
    .nav-link {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--primary);
      position: relative;
      padding: 0.5rem 0;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--accent);
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 0.65rem 1.4rem;
      font-size: 0.95rem;
      font-weight: 600;
      border-radius: var(--radius);
      cursor: pointer;
      border: 1px solid transparent;
      transition: all 0.25s ease;
      white-space: nowrap;
    }
    .btn-cta {
      background-color: var(--cta);
      color: #ffffff;
    }
    .btn-cta:hover {
      background-color: var(--cta-hover);
      box-shadow: 0 4px 12px rgba(243, 106, 34, 0.28);
    }
    .btn-outline {
      border-color: var(--accent);
      color: var(--accent);
      background: transparent;
    }
    .btn-outline:hover {
      background: var(--accent);
      color: #ffffff;
    }
    .btn-white {
      background: #ffffff;
      color: var(--primary);
    }
    .btn-white:hover {
      background: #f1f5f9;
    }

    /* 板块通用 */
    .section-wrap {
      padding: 5rem 0;
    }
    .section-alt {
      background-color: #ffffff;
    }
    .section-dark {
      background-color: var(--bg-dark);
      color: #F8FAFC;
    }
    .section-header {
      margin-bottom: 3rem;
      max-width: 760px;
    }
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.02em;
      margin-bottom: 0.75rem;
      position: relative;
    }
    .section-dark .section-title {
      color: #ffffff;
    }
    .section-desc {
      font-size: 1.05rem;
      color: var(--text-muted);
      line-height: 1.7;
    }
    .section-dark .section-desc {
      color: #94A3B8;
    }
    .badge {
      display: inline-block;
      padding: 0.25rem 0.75rem;
      background: rgba(13, 130, 138, 0.1);
      color: var(--accent);
      font-size: 0.8rem;
      font-weight: 600;
      border-radius: 4px;
      margin-bottom: 0.75rem;
    }
    .badge-dark {
      background: rgba(255, 255, 255, 0.1);
      color: #38BDF8;
    }

    /* Hero */
    .hero-section {
      background: linear-gradient(135deg, #10161C 0%, #1A232A 100%);
      color: #ffffff;
      padding: 4.5rem 0 5.5rem;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.15fr 0.85fr;
      gap: 3.5rem;
      align-items: center;
    }
    .hero-h1 {
      font-size: 2.85rem;
      line-height: 1.25;
      font-weight: 800;
      letter-spacing: -0.025em;
      margin-bottom: 1.25rem;
      color: #FFFFFF;
    }
    .hero-h1 span {
      color: #38BDF8;
    }
    .hero-intro {
      font-size: 1.08rem;
      color: #CBD5E1;
      margin-bottom: 2rem;
      line-height: 1.8;
    }
    .hero-btns {
      display: flex;
      gap: 1rem;
      margin-bottom: 2.5rem;
    }
    .hero-rank-panel {
      background: #171F26;
      border: 1px solid #2B353E;
      border-radius: var(--radius);
      padding: 1.5rem;
      box-shadow: var(--shadow-lg);
    }
    .rank-panel-title {
      font-size: 1.1rem;
      font-weight: 700;
      color: #E2E8F0;
      margin-bottom: 1rem;
      border-bottom: 1px solid #2B353E;
      padding-bottom: 0.75rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .rank-item {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0.75rem 0;
      border-bottom: 1px solid #222B33;
      font-size: 0.9rem;
    }
    .rank-item:last-child {
      border-bottom: none;
    }
    .rank-badge {
      width: 22px;
      height: 22px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      background: var(--accent);
      color: #fff;
      font-size: 0.75rem;
      border-radius: 4px;
      margin-right: 0.5rem;
    }

    /* 网格卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.75rem;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 2rem;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
    }
    .card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 1.75rem;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-3px);
      border-color: var(--accent);
    }
    .card-title {
      font-size: 1.25rem;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 0.75rem;
    }
    .card-desc {
      font-size: 0.925rem;
      color: var(--text-muted);
      line-height: 1.65;
    }
    .card-img-top {
      border-radius: 6px;
      overflow: hidden;
      margin-bottom: 1.25rem;
      aspect-ratio: 16/10;
      background-color: #EEF2F6;
    }
    .card-img-top img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    /* 热门产品卡片定制 */
    .product-card {
      display: flex;
      flex-direction: column;
      height: 100%;
    }
    .product-spec-list {
      list-style: none;
      margin: 1rem 0 1.25rem;
      padding-top: 0.75rem;
      border-top: 1px dashed var(--border-color);
      font-size: 0.875rem;
      color: #475569;
    }
    .product-spec-list li {
      margin-bottom: 0.35rem;
      display: flex;
      justify-content: space-between;
    }

    /* 指标横幅 */
    .metric-banner {
      background: var(--accent);
      color: #ffffff;
      padding: 3.5rem 0;
    }
    .metric-item {
      text-align: center;
    }
    .metric-number {
      font-size: 2.75rem;
      font-weight: 800;
      line-height: 1;
      margin-bottom: 0.5rem;
      font-family: Consolas, monospace, sans-serif;
    }
    .metric-label {
      font-size: 0.95rem;
      opacity: 0.9;
    }

    /* FAQ 手风琴 */
    .faq-wrapper {
      max-width: 860px;
      margin: 0 auto;
    }
    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      margin-bottom: 1rem;
      overflow: hidden;
    }
    .faq-trigger {
      width: 100%;
      text-align: left;
      padding: 1.25rem 1.5rem;
      font-size: 1.05rem;
      font-weight: 600;
      color: var(--primary);
      background: none;
      border: none;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-content {
      padding: 0 1.5rem 1.25rem;
      color: var(--text-muted);
      font-size: 0.95rem;
      line-height: 1.7;
      display: none;
    }
    .faq-item.active .faq-content {
      display: block;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }
    .faq-icon {
      transition: transform 0.25s ease;
      font-size: 0.85rem;
    }

    /* 需求表单 */
    .lead-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 12px;
      padding: 2.5rem;
      box-shadow: var(--shadow-md);
    }
    .form-group {
      margin-bottom: 1.25rem;
    }
    .form-label {
      display: block;
      font-size: 0.9rem;
      font-weight: 600;
      margin-bottom: 0.4rem;
      color: var(--primary);
    }
    .form-control {
      width: 100%;
      padding: 0.75rem 1rem;
      font-size: 0.95rem;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      outline: none;
      transition: border-color 0.2s;
    }
    .form-control:focus {
      border-color: var(--accent);
      box-shadow: 0 0 0 3px rgba(13, 130, 138, 0.15);
    }
    .radio-group {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 0.75rem;
    }
    .radio-label {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      padding: 0.6rem 0.85rem;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      cursor: pointer;
      font-size: 0.875rem;
    }

    /* 页脚 */
    .footer {
      background-color: var(--primary);
      color: #94A3B8;
      padding: 4.5rem 0 2rem;
      border-top: 1px solid #28313A;
      font-size: 0.925rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1fr;
      gap: 2.5rem;
      margin-bottom: 3.5rem;
    }
    .footer-title {
      font-size: 1.05rem;
      font-weight: 600;
      color: #FFFFFF;
      margin-bottom: 1.25rem;
    }
    .footer-list {
      list-style: none;
    }
    .footer-list li {
      margin-bottom: 0.65rem;
    }
    .footer-list a:hover {
      color: #38BDF8;
    }
    .footer-bottom {
      padding-top: 1.75rem;
      border-top: 1px solid #2A343D;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 1rem;
      font-size: 0.85rem;
    }

    /* 移动端吸底条 */
    .mobile-cta-bar {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      right: 0;
      background: #FFFFFF;
      border-top: 1px solid var(--border-color);
      padding: 0.75rem 1rem;
      z-index: 999;
      box-shadow: 0 -4px 12px rgba(0,0,0,0.06);
    }
    .mobile-cta-grid {
      display: grid;
      grid-template-columns: 1fr 1.6fr;
      gap: 0.75rem;
    }

    /* 移动响应式 */
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .hero-grid { grid-template-columns: 1fr; gap: 2.5rem; }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .grid-3, .grid-2, .grid-4 { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-h1 { font-size: 2.15rem; }
      .section-wrap { padding: 3.5rem 0; }
      .mobile-cta-bar { display: block; }
      body { padding-bottom: 64px; }
      .hero-btns { flex-direction: column; }
    }