/* roulang page: index */
:root {
      --primary: #4F46E5;
      --primary-hover: #4338CA;
      --accent: #06B6D4;
      --success: #10B981;
      --bg-main: #FFFFFF;
      --bg-alt: #F8FAFC;
      --bg-dark: #0B0F19;
      --bg-card: #FFFFFF;
      --text-title: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --text-light: #F1F5F9;
      --border-color: #E2E8F0;
      --border-dark: #1E293B;
      --radius-sm: 6px;
      --radius-md: 12px;
      --radius-full: 9999px;
      --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
      --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
      --font-stack: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    }

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

    body {
      font-family: var(--font-stack);
      color: var(--text-body);
      background-color: var(--bg-main);
      line-height: 1.75;
      letter-spacing: 0.02em;
      -webkit-font-smoothing: antialiased;
    }

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

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

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

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    .top-bar {
      background-color: var(--bg-dark);
      color: #94A3B8;
      font-size: 0.8125rem;
      padding: 0.5rem 0;
      border-bottom: 1px solid var(--border-dark);
    }
    .top-bar-flex {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 0.5rem;
    }
    .top-bar-contact {
      display: flex;
      gap: 1.5rem;
    }

    .header-main {
      position: sticky;
      top: 0;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      z-index: 1000;
      border-bottom: 1px solid var(--border-color);
    }
    .header-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 72px;
    }
    .logo-box {
      font-size: 1.5rem;
      font-weight: 800;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .logo-badge {
      font-size: 0.75rem;
      background: #EEF2FF;
      color: var(--primary);
      padding: 0.15rem 0.5rem;
      border-radius: var(--radius-sm);
      font-weight: 600;
    }
    .main-nav {
      display: flex;
      align-items: center;
      gap: 1.75rem;
    }
    .nav-link {
      font-weight: 500;
      color: var(--text-title);
      font-size: 0.95rem;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary);
    }
    .nav-cta-btn {
      background: var(--primary);
      color: #fff;
      padding: 0.55rem 1.25rem;
      border-radius: var(--radius-full);
      font-size: 0.875rem;
      font-weight: 600;
    }
    .nav-cta-btn:hover {
      background: var(--primary-hover);
      color: #fff;
    }
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--text-title);
      cursor: pointer;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 0.75rem 1.75rem;
      font-size: 0.95rem;
      font-weight: 600;
      border-radius: var(--radius-sm);
      cursor: pointer;
      border: 1px solid transparent;
      transition: all 0.25s ease;
      gap: 0.5rem;
    }
    .btn-primary {
      background: var(--primary);
      color: #FFFFFF;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
    }
    .btn-secondary {
      background: #FFFFFF;
      color: var(--text-title);
      border-color: var(--border-color);
    }
    .btn-secondary:hover {
      background: #F1F5F9;
      border-color: #CBD5E1;
    }
    .badge {
      display: inline-flex;
      align-items: center;
      font-size: 0.75rem;
      font-weight: 600;
      padding: 0.25rem 0.75rem;
      border-radius: var(--radius-full);
      background: #EEF2FF;
      color: var(--primary);
    }

    section {
      padding: 80px 0;
    }
    .section-light {
      background-color: var(--bg-main);
    }
    .section-gray {
      background-color: var(--bg-alt);
    }
    .section-dark {
      background-color: var(--bg-dark);
      color: var(--text-light);
    }
    .section-header {
      margin-bottom: 3.5rem;
      max-width: 760px;
    }
    .section-header h2 {
      font-size: 2.125rem;
      line-height: 1.3;
      color: var(--text-title);
      margin-bottom: 1rem;
      font-weight: 700;
    }
    .section-dark .section-header h2 {
      color: #FFFFFF;
    }
    .section-desc {
      font-size: 1rem;
      color: var(--text-muted);
      line-height: 1.8;
    }
    .section-dark .section-desc {
      color: #94A3B8;
    }

    .hero-section {
      position: relative;
      background: linear-gradient(135deg, rgba(11, 15, 25, 0.92) 0%, rgba(15, 23, 42, 0.85) 100%),
                  url('/assets/images/体育数据可视化_你想知道的方法都在这里_---知乎.jpg') center/cover no-repeat;
      color: #FFFFFF;
      padding: 90px 0;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.15fr 0.85fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 2.75rem;
      line-height: 1.25;
      font-weight: 800;
      margin: 1.25rem 0;
      color: #FFFFFF;
    }
    .hero-lead {
      font-size: 1.05rem;
      line-height: 1.8;
      color: #CBD5E1;
      margin-bottom: 2rem;
    }
    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      margin-bottom: 2.5rem;
    }
    .hero-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 0.75rem;
    }
    .hero-tag-item {
      background: rgba(255, 255, 255, 0.1);
      border: 1px solid rgba(255, 255, 255, 0.2);
      padding: 0.35rem 0.85rem;
      border-radius: var(--radius-sm);
      font-size: 0.8125rem;
      color: #E2E8F0;
    }
    
    .countdown-box {
      background: rgba(15, 23, 42, 0.85);
      border: 1px solid rgba(255, 255, 255, 0.15);
      border-radius: var(--radius-md);
      padding: 2rem;
      box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
      backdrop-filter: blur(16px);
    }
    .countdown-header {
      font-size: 1.125rem;
      font-weight: 700;
      color: #FFFFFF;
      margin-bottom: 1.5rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .countdown-timer {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 0.75rem;
      margin-bottom: 1.75rem;
      text-align: center;
    }
    .timer-block {
      background: rgba(30, 41, 59, 0.8);
      border: 1px solid rgba(255, 255, 255, 0.08);
      padding: 0.75rem 0.5rem;
      border-radius: var(--radius-sm);
    }
    .timer-num {
      font-size: 1.75rem;
      font-weight: 800;
      color: var(--accent);
      display: block;
      line-height: 1.2;
    }
    .timer-label {
      font-size: 0.75rem;
      color: #94A3B8;
    }
    .countdown-specs {
      list-style: none;
      margin-bottom: 1.5rem;
    }
    .countdown-specs li {
      font-size: 0.875rem;
      color: #CBD5E1;
      padding: 0.4rem 0;
      display: flex;
      justify-content: space-between;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }
    .countdown-specs li span:last-child {
      color: #FFFFFF;
      font-weight: 600;
    }

    .about-engine-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3.5rem;
      align-items: center;
    }
    .code-console {
      background: #0F172A;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-lg);
      border: 1px solid #1E293B;
    }
    .console-header {
      background: #1E293B;
      padding: 0.75rem 1rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
    }
    .dot-red { background: #EF4444; }
    .dot-yellow { background: #F59E0B; }
    .dot-green { background: #10B981; }
    .console-title {
      font-size: 0.75rem;
      color: #94A3B8;
      margin-left: 0.5rem;
      font-family: monospace;
    }
    .console-body {
      padding: 1.5rem;
      font-family: monospace;
      font-size: 0.85rem;
      color: #E2E8F0;
      line-height: 1.7;
    }
    .code-hl-k { color: #818CF8; }
    .code-hl-f { color: #38BDF8; }
    .code-hl-s { color: #34D399; }
    .spec-table-row {
      display: flex;
      justify-content: space-between;
      padding: 0.85rem 0;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.925rem;
    }
    .spec-table-row strong {
      color: var(--text-title);
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.75rem;
    }
    .feature-card {
      background: #FFFFFF;
      padding: 2.25rem 1.75rem;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
      box-shadow: var(--shadow-sm);
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
      border-color: #C7D2FE;
    }
    .feature-icon-badge {
      width: 48px;
      height: 48px;
      background: #EEF2FF;
      color: var(--primary);
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.25rem;
      font-weight: bold;
      margin-bottom: 1.25rem;
    }
    .feature-card h3 {
      font-size: 1.25rem;
      color: var(--text-title);
      margin-bottom: 0.75rem;
      font-weight: 700;
    }
    .feature-card p {
      font-size: 0.925rem;
      color: var(--text-muted);
      line-height: 1.7;
    }

    .solution-card {
      background: #FFFFFF;
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      transition: all 0.3s ease;
    }
    .solution-card:hover {
      box-shadow: var(--shadow-lg);
      border-color: #C7D2FE;
    }
    .solution-img-box {
      height: 220px;
      overflow: hidden;
      position: relative;
    }
    .solution-img-box img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }
    .solution-card:hover .solution-img-box img {
      transform: scale(1.05);
    }
    .solution-body {
      padding: 1.75rem;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .solution-body h3 {
      font-size: 1.25rem;
      color: var(--text-title);
      margin: 0.5rem 0 0.75rem;
      font-weight: 700;
    }
    .solution-body p {
      font-size: 0.9rem;
      color: var(--text-muted);
      margin-bottom: 1.25rem;
      flex: 1;
    }
    .solution-specs {
      list-style: none;
      margin-bottom: 1.5rem;
    }
    .solution-specs li {
      font-size: 0.85rem;
      color: var(--text-body);
      padding: 0.35rem 0;
      position: relative;
      padding-left: 1.25rem;
    }
    .solution-specs li::before {
      content: "✓";
      position: absolute;
      left: 0;
      color: var(--success);
      font-weight: bold;
    }

    .case-container {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 3.5rem;
      align-items: center;
    }
    .case-visual {
      position: relative;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: 0 25px 50px -12px rgba(0,0,0,0.6);
      border: 1px solid var(--border-dark);
    }
    .case-visual img {
      width: 100%;
      height: auto;
    }
    .case-info h3 {
      font-size: 1.85rem;
      color: #FFFFFF;
      margin-bottom: 1rem;
    }
    .case-metrics-row {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.25rem;
      margin: 2rem 0;
    }
    .case-metric-box {
      background: #1E293B;
      border: 1px solid rgba(255,255,255,0.06);
      padding: 1rem;
      border-radius: var(--radius-sm);
    }
    .case-metric-box .c-num {
      font-size: 1.75rem;
      font-weight: 800;
      color: var(--accent);
      display: block;
    }
    .case-metric-box .c-lbl {
      font-size: 0.75rem;
      color: #94A3B8;
    }

    .story-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
    }
    .story-card {
      background: #FFFFFF;
      border-radius: var(--radius-md);
      padding: 2.25rem;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .story-role-tag {
      font-size: 0.75rem;
      background: #F1F5F9;
      color: var(--text-title);
      padding: 0.25rem 0.6rem;
      border-radius: var(--radius-sm);
      font-weight: 600;
      margin-bottom: 1rem;
      display: inline-block;
    }
    .story-card h3 {
      font-size: 1.25rem;
      margin-bottom: 1rem;
      color: var(--text-title);
    }
    .compare-bar-box {
      margin: 1.5rem 0;
      background: #F8FAFC;
      padding: 1.25rem;
      border-radius: var(--radius-sm);
      border: 1px solid var(--border-color);
    }
    .bar-line {
      margin-bottom: 0.75rem;
    }
    .bar-line-header {
      display: flex;
      justify-content: space-between;
      font-size: 0.8125rem;
      margin-bottom: 0.25rem;
    }
    .bar-track {
      height: 8px;
      background: #E2E8F0;
      border-radius: 4px;
      overflow: hidden;
    }
    .bar-fill-old { width: 100%; background: #94A3B8; height: 100%; }
    .bar-fill-new { width: 35%; background: var(--primary); height: 100%; }

    .metrics-strip {
      background: #1E293B;
      border-top: 1px solid #334155;
      border-bottom: 1px solid #334155;
      padding: 50px 0;
      color: #FFFFFF;
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
    }
    .metric-item .big-number {
      font-size: 2.75rem;
      font-weight: 800;
      color: #38BDF8;
      line-height: 1.1;
      margin-bottom: 0.5rem;
    }
    .metric-item .label-text {
      font-size: 0.9rem;
      color: #94A3B8;
      font-weight: 500;
    }

    .review-card {
      background: #FFFFFF;
      padding: 2rem;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .review-stars {
      color: #F59E0B;
      margin-bottom: 1rem;
      font-size: 0.9rem;
    }
    .review-quote {
      font-size: 0.95rem;
      color: var(--text-body);
      line-height: 1.7;
      margin-bottom: 1.5rem;
      font-style: italic;
    }
    .reviewer-info {
      display: flex;
      align-items: center;
      gap: 0.75rem;
    }
    .reviewer-avatar-placeholder {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: #E0E7FF;
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
    }
    .reviewer-name {
      font-weight: 700;
      color: var(--text-title);
      font-size: 0.95rem;
    }
    .reviewer-title {
      font-size: 0.8125rem;
      color: var(--text-muted);
    }

    .news-card {
      background: #FFFFFF;
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-color);
      display: flex;
      flex-direction: column;
    }
    .news-body {
      padding: 1.75rem;
      display: flex;
      flex-direction: column;
      flex: 1;
    }
    .news-date {
      font-size: 0.8125rem;
      color: var(--text-muted);
      margin-bottom: 0.5rem;
    }
    .news-card h3 {
      font-size: 1.15rem;
      color: var(--text-title);
      margin-bottom: 0.75rem;
      line-height: 1.4;
    }
    .news-card p {
      font-size: 0.875rem;
      color: var(--text-muted);
      margin-bottom: 1.5rem;
      flex: 1;
    }
    .news-link {
      font-size: 0.875rem;
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 0.25rem;
    }

    .faq-accordion {
      max-width: 860px;
      margin: 0 auto;
    }
    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      margin-bottom: 1rem;
      overflow: hidden;
    }
    .faq-question {
      padding: 1.25rem 1.5rem;
      font-size: 1.05rem;
      font-weight: 600;
      color: var(--text-title);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
      background: #FFFFFF;
      border: none;
      width: 100%;
      text-align: left;
    }
    .faq-icon {
      font-size: 1.25rem;
      transition: transform 0.3s ease;
      color: var(--primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      background: #FAFAFA;
      color: var(--text-body);
      font-size: 0.925rem;
      line-height: 1.8;
      padding: 0 1.5rem;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 1.25rem 1.5rem;
      border-top: 1px solid var(--border-color);
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    .guarantee-bar {
      background: #FFFFFF;
      border-top: 1px solid var(--border-color);
      border-bottom: 1px solid var(--border-color);
      padding: 40px 0;
    }
    .guarantee-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
    }
    .guarantee-item {
      display: flex;
      align-items: flex-start;
      gap: 1rem;
    }
    .guarantee-icon {
      font-size: 1.75rem;
      color: var(--primary);
      line-height: 1;
    }
    .guarantee-item h4 {
      font-size: 1rem;
      color: var(--text-title);
      margin-bottom: 0.25rem;
    }
    .guarantee-item p {
      font-size: 0.8125rem;
      color: var(--text-muted);
    }

    .cta-card {
      background: linear-gradient(135deg, #1E1B4B 0%, #0F172A 100%);
      border-radius: var(--radius-md);
      padding: 3.5rem 3rem;
      color: #FFFFFF;
      box-shadow: var(--shadow-lg);
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;gap: 3rem;
      align-items: center;
    }
    .cta-content h2 {
      font-size: 2.25rem;
      line-height: 1.3;
      margin-bottom: 1rem;
      color: #FFFFFF;
    }
    .cta-content p {
      font-size: 1rem;
      color: #CBD5E1;
      margin-bottom: 1.5rem;
    }
    .cta-perks {
      list-style: none;
      margin-bottom: 2rem;
    }
    .cta-perks li {
      font-size: 0.875rem;
      color: #E2E8F0;
      margin-bottom: 0.5rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .cta-form {
      background: #FFFFFF;
      padding: 2rem;
      border-radius: var(--radius-sm);
      color: var(--text-body);
    }
    .form-group {
      margin-bottom: 1.25rem;
    }
    .form-group label {
      display: block;
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--text-title);
      margin-bottom: 0.35rem;
    }
    .form-control {
      width: 100%;
      padding: 0.75rem;
      font-size: 0.9rem;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      outline: none;
      transition: border-color 0.2s ease;
    }
    .form-control:focus {
      border-color: var(--primary);
    }
    .form-btn {
      width: 100%;
      padding: 0.85rem;
      font-size: 1rem;
    }

    footer {
      background-color: var(--bg-dark);
      color: #94A3B8;
      padding: 70px 0 30px;
      font-size: 0.875rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.4fr 0.8fr 0.9fr 0.9fr;
      gap: 3rem;
      margin-bottom: 3.5rem;
    }
    .footer-brand h4 {
      font-size: 1.25rem;
      color: #FFFFFF;
      margin-bottom: 1rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .footer-brand p {
      line-height: 1.7;
      margin-bottom: 1.5rem;
      font-size: 0.875rem;
    }
    .footer-col h5 {
      font-size: 0.95rem;
      color: #FFFFFF;
      margin-bottom: 1.25rem;
      font-weight: 600;
    }
    .footer-links {
      list-style: none;
    }
    .footer-links li {
      margin-bottom: 0.65rem;
    }
    .footer-links a:hover {
      color: #FFFFFF;
    }
    .footer-bottom {
      border-top: 1px solid var(--border-dark);
      padding-top: 1.5rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 1rem;
      font-size: 0.8125rem;
    }

    @media (max-width: 1024px) {
      .hero-grid, .about-engine-grid, .case-container, .cta-card {
        grid-template-columns: 1fr;
        gap: 2.5rem;
      }
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
      }
      .guarantee-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      section {
        padding: 48px 0;
      }
      .hero-section {
        padding: 50px 0;
      }
      .hero-content h1 {
        font-size: 2rem;
      }
      .main-nav {
        display: none;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .grid-3, .story-grid, .guarantee-grid, .footer-grid, .metrics-grid {
        grid-template-columns: 1fr;
      }
      .case-metrics-row {
        grid-template-columns: 1fr;
      }
      .top-bar-contact {
        display: none;
      }
      .cta-card {
        padding: 2rem 1.5rem;
      }
      .cta-content h2 {
        font-size: 1.65rem;
      }
      .countdown-timer {
        grid-template-columns: repeat(2, 1fr);
      }
    }