/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3A5AD9;
      --green: #00B578;
      --orange: #FF9F0A;
      --red: #FA5151;
      --bg: #F5F6FA;
      --white: #FFFFFF;
      --text: #1F2329;
      --text-light: #86909C;
      --border-light: #E8EAED;
      --shadow-card: 0 4px 16px rgba(31, 35, 41, 0.06);
      --shadow-hover: 0 8px 24px rgba(31, 35, 41, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-large: 16px;
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input, textarea {
      font-family: inherit;
    }
    .section-spacing {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      .section-spacing {
        padding: 60px 0;
      }
    }
    /* 导航 PC */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0,0,0,0.02);
      transition: var(--transition);
    }
    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: baseline;
      gap: 8px;
    }
    .logo-text {
      font-size: 24px;
      font-weight: 700;
      color: var(--text);
      letter-spacing: 0.5px;
    }
    .logo-domain {
      font-size: 12px;
      color: var(--text-light);
      font-weight: 400;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text);
      transition: color 0.2s;
      padding: 4px 0;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .mobile-nav {
      display: none;
    }
    @media (max-width: 768px) {
      .nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        z-index: 100;
        background: rgba(255,255,255,0.95);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        border-top: 1px solid var(--border-light);
        justify-content: space-around;
        padding: 8px 12px 16px;
        border-radius: 24px 24px 0 0;
        box-shadow: 0 -4px 12px rgba(0,0,0,0.02);
      }
      .mobile-nav-item {
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 4px;
        font-size: 11px;
        color: var(--text-light);
        font-weight: 500;
        transition: var(--transition);
        padding: 6px 12px;
        border-radius: 20px;
      }
      .mobile-nav-item.active {
        background: var(--primary);
        color: white;
        font-weight: 600;
      }
      .mobile-nav-item i {
        font-size: 18px;
      }
    }
    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background: linear-gradient(180deg, #F5F6FA 0%, #FFFFFF 100%);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero-title {
      font-size: 40px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text);
      margin-bottom: 16px;
    }
    .hero-sub {
      font-size: 16px;
      color: var(--text-light);
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      transition: var(--transition);
      cursor: pointer;
      border: none;
      background: transparent;
      line-height: 1.2;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      box-shadow: 0 4px 12px rgba(78,110,242,0.25);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-1px);
    }
    .btn-secondary {
      background: rgba(78,110,242,0.08);
      color: var(--primary);
    }
    .btn-secondary:hover {
      background: rgba(78,110,242,0.15);
    }
    .data-board {
      background: rgba(255,255,255,0.7);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-large);
      padding: 28px;
      display: flex;
      flex-direction: column;
      gap: 24px;
      box-shadow: var(--shadow-card);
    }
    .metric {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .metric-label {
      font-size: 15px;
      color: var(--text-light);
    }
    .metric-value {
      font-size: 28px;
      font-weight: 700;
      font-variant-numeric: tabular-nums;
      color: var(--text);
    }
    .green-badge {
      color: var(--green);
      font-size: 14px;
      margin-left: 6px;
    }
    .progress-ring {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: conic-gradient(var(--primary) 0deg 260deg, #E8EAED 260deg 360deg);
      position: relative;
    }
    .progress-ring::after {
      content: "92%";
      position: absolute;
      inset: 6px;
      background: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 12px;
      font-weight: 700;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        gap: 40px;
      }
      .hero-title {
        font-size: 32px;
      }
      .data-board {
        padding: 20px;
      }
    }
    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: 1.3fr 1fr 1fr;
      gap: 24px;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      cursor: default;
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .service-card.large {
      grid-row: span 1;
      min-height: 420px;
    }
    .service-card.medium {
      min-height: 360px;
    }
    .service-icon {
      font-size: 36px;
      color: var(--primary);
      margin-bottom: 20px;
      transition: transform 0.2s;
    }
    .service-card:hover .service-icon {
      transform: rotate(5deg);
    }
    .service-title {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .service-desc {
      color: var(--text-light);
      font-size: 15px;
      line-height: 1.6;
      flex: 1;
    }
    .service-link {
      margin-top: 20px;
      color: var(--primary);
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    @media (max-width: 768px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
      .service-card.large, .service-card.medium {
        min-height: auto;
      }
    }
    /* 结果对比 */
    .compare-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 0;
      position: relative;
      background: white;
      border-radius: var(--radius-large);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .compare-left, .compare-right {
      padding: 40px;
    }
    .compare-left {
      background: #E8EAED;
      color: #5E6470;
    }
    .compare-right {
      background: white;
      border-left: 4px solid var(--primary);
    }
    .compare-title {
      font-size: 18px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .compare-stat {
      font-size: 28px;
      font-weight: 700;
      margin: 8px 0;
    }
    .growth-tag {
      color: var(--green);
      font-weight: 600;
      margin-left: 8px;
    }
    .slider-handle {
      position: absolute;
      left: 50%;
      top: 50%;
      transform: translate(-50%, -50%);
      width: 32px;
      height: 32px;
      background: white;
      border: 2px solid var(--primary);
      border-radius: 50%;
      cursor: col-resize;
      z-index: 5;
      box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    }
    @media (max-width: 768px) {
      .compare-wrapper {
        grid-template-columns: 1fr;
      }
      .slider-handle {
        display: none;
      }
      .compare-right {
        border-left: none;
        border-top: 4px solid var(--primary);
      }
    }
    /* 信任带 */
    .trust-strip {
      background: white;
      border-radius: var(--radius-card);
      padding: 40px 24px;
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 24px;
      box-shadow: var(--shadow-card);
    }
    .trust-item {
      text-align: center;
    }
    .trust-number {
      font-size: 38px;
      font-weight: 700;
      color: var(--primary);
    }
    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      padding: 20px;
      box-shadow: var(--shadow-card);
      cursor: pointer;
      transition: var(--transition);
    }
    .faq-question {
      display: flex;
      align-items: center;
      gap: 12px;
      font-weight: 600;
    }
    .faq-icon {
      color: var(--primary);
      font-size: 20px;
      transition: transform 0.2s;
      width: 24px;
    }
    .faq-answer {
      margin-top: 12px;
      padding-left: 36px;
      border-left: 3px solid var(--primary);
      color: var(--text-light);
      display: none;
      font-size: 15px;
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    @media (max-width: 768px) {
      .faq-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 表单 */
    .contact-card {
      background: white;
      border-radius: var(--radius-large);
      padding: 48px;
      box-shadow: var(--shadow-card);
      max-width: 640px;
      margin: 0 auto;
    }
    .input-field {
      width: 100%;
      padding: 14px 16px;
      background: #F5F6FA;
      border: 1px solid transparent;
      border-radius: var(--radius-btn);
      margin-bottom: 20px;
      font-size: 15px;
      transition: 0.15s;
    }
    .input-field:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(78,110,242,0.15);
    }
    .btn-full {
      width: 100%;
    }
    /* 页脚 */
    .footer {
      background: #1F2329;
      color: #CFD3DC;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer-logo {
      font-size: 22px;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }
    .social-icons i {
      font-size: 20px;
      margin-right: 16px;
      color: #9AA1B0;
      transition: 0.2s;
    }
    .social-icons i:hover {
      color: var(--primary);
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .contact-card {
        padding: 28px;
      }
    }
    h2 {
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 32px;
    }
    .count-up {
      transition: 0.1s linear;
    }