/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-hover: #154DB8;
      --accent: #FF6A3D;
      --accent-hover: #E55D2D;
      --bg: #FAFBFD;
      --surface: #FFFFFF;
      --bg-soft: #F1F5F9;
      --text-deep: #0B1E3C;
      --text-heading: #1A1F36;
      --text-body: #475569;
      --text-muted: #64748B;
      --border-light: #E2E8F0;
      --shadow-sm: 0 4px 14px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --radius-lg: 16px;
      --font-system: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1280px;
    }

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

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

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

    a {
      text-decoration: none;
      color: inherit;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: #FFFFFF;
      box-shadow: 0 1px 0 var(--border-light);
      z-index: 100;
      display: flex;
      align-items: center;
    }

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

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--text-deep);
      letter-spacing: 1px;
    }
    .logo span {
      color: var(--primary);
    }

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

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-body);
      transition: color 0.2s;
      padding: 8px 0;
    }

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

    .mobile-nav {
      display: none;
    }

    /* 底部胶囊导航 (移动端) */
    .bottom-capsule {
      display: none;
    }

    @media (max-width: 768px) {
      .header .nav-links {
        display: none;
      }
      .mobile-nav {
        display: none;
      }
      .bottom-capsule {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        background: #FFFFFF;
        border-top: 1px solid var(--border-light);
        justify-content: space-around;
        align-items: center;
        padding: 8px 16px;
        z-index: 100;
        backdrop-filter: blur(10px);
        background: rgba(255,255,255,0.95);
      }
      .bottom-capsule a {
        display: flex;
        flex-direction: column;
        align-items: center;
        font-size: 12px;
        color: var(--text-muted);
        gap: 4px;
        font-weight: 500;
        transition: color 0.2s;
      }
      .bottom-capsule a i {
        font-size: 18px;
      }
      .bottom-capsule a.active {
        color: var(--primary);
      }
      body {
        padding-bottom: 80px;
      }
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 64px 0;
      }
    }

    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      font-size: 26px;
      font-weight: 600;
      color: var(--text-deep);
      margin-bottom: 12px;
    }
    .section-title p {
      font-size: 16px;
      color: var(--text-muted);
      max-width: 600px;
      margin: 0 auto;
    }

    /* 按钮 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: all 0.2s ease;
      cursor: pointer;
      border: none;
      background: transparent;
      line-height: 1.2;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
    }
    .btn-outline {
      border: 1.5px solid var(--primary);
      color: var(--primary);
      background: transparent;
    }
    .btn-outline:hover {
      background: #EBF2FF;
    }
    .btn-accent {
      background: var(--accent);
      color: white;
    }
    .btn-accent:hover {
      background: var(--accent-hover);
    }

    /* Hero */
    .hero {
      padding-top: 140px;
      padding-bottom: 80px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 32px;
      font-weight: 700;
      color: var(--text-deep);
      line-height: 1.3;
      margin-bottom: 20px;
    }
    .hero-text p {
      font-size: 18px;
      color: var(--text-body);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      border-radius: 20px;
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
        gap: 40px;
      }
      .hero-text h1 {
        font-size: 24px;
      }
    }

    /* 核心优势 左对齐卡片列表 */
    .features-list {
      display: flex;
      flex-direction: column;
      gap: 28px;
      max-width: 900px;
      margin: 0 auto;
    }
    .feature-item {
      display: flex;
      gap: 24px;
      background: var(--surface);
      padding: 28px 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      border-bottom: 2px solid var(--primary);
      transition: box-shadow 0.2s;
      align-items: flex-start;
    }
    .feature-item:hover {
      box-shadow: var(--shadow-md);
    }
    .feature-icon {
      font-size: 28px;
      color: var(--primary);
      min-width: 40px;
    }
    .feature-content h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--text-heading);
      margin-bottom: 8px;
    }
    .feature-content p {
      color: var(--text-body);
    }
    @media (max-width: 768px) {
      .feature-item {
        flex-direction: column;
        gap: 12px;
      }
    }

    /* 数据板块 */
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }
    .data-item .number {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }
    .data-item .label {
      font-size: 14px;
      color: var(--text-muted);
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .data-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
      }
      .data-item .number {
        font-size: 28px;
      }
    }

    /* 案例卡片 */
    .cases-grid {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }
    .case-card {
      display: flex;
      background: var(--surface);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: box-shadow 0.2s;
    }
    .case-card:hover {
      box-shadow: var(--shadow-md);
    }
    .case-img {
      width: 45%;
      min-height: 240px;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-info {
      padding: 32px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .case-info h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--text-heading);
      margin-bottom: 12px;
    }
    .case-info p {
      color: var(--text-body);
      margin-bottom: 16px;
    }
    .text-link {
      color: var(--primary);
      font-weight: 500;
      font-size: 15px;
    }
    @media (max-width: 768px) {
      .case-card {
        flex-direction: column;
      }
      .case-img {
        width: 100%;
      }
    }

    /* 流程步骤 */
    .steps-row {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      position: relative;
    }
    .step {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      flex: 1;
      position: relative;
    }
    .step-circle {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: white;
      border: 2px solid var(--border-light);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--text-muted);
      margin-bottom: 16px;
      z-index: 2;
      background: var(--surface);
    }
    .step.active .step-circle {
      background: var(--primary);
      border-color: var(--primary);
      color: white;
    }
    .step h4 {
      font-weight: 600;
      color: var(--text-heading);
      margin-bottom: 6px;
    }
    .step p {
      font-size: 14px;
      color: var(--text-muted);
      max-width: 160px;
    }
    .step-line {
      position: absolute;
      top: 20px;
      left: 50%;
      width: 100%;
      height: 2px;
      background: var(--border-light);
      z-index: 1;
    }
    .step:last-child .step-line {
      display: none;
    }
    @media (max-width: 768px) {
      .steps-row {
        flex-direction: column;
        gap: 32px;
        align-items: flex-start;
      }
      .step {
        flex-direction: row;
        text-align: left;
        gap: 16px;
        width: 100%;
      }
      .step-line {
        display: none;
      }
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      margin-bottom: 12px;
      border-radius: var(--radius-card);
      background: var(--surface);
      overflow: hidden;
      transition: all 0.3s ease;
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 500;
      font-size: 18px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-heading);
      background: var(--surface);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: #F8FAFC;
      padding: 0 24px;
      color: var(--text-body);
      border-left: 3px solid transparent;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 16px 24px;
      border-left-color: var(--primary);
    }
    .faq-item.open .faq-question {
      color: var(--primary);
    }

    /* CTA */
    .cta-block {
      background: var(--primary);
      text-align: center;
      padding: 80px 0;
    }
    .cta-block h2 {
      font-size: 28px;
      color: white;
      margin-bottom: 16px;
    }
    .cta-block p {
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
    }
    .cta-buttons {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }

    /* 页脚 */
    .footer {
      background: #0B1E3C;
      color: #CBD5E1;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 32px;
    }
    .footer h4 {
      color: white;
      margin-bottom: 16px;
    }
    .footer p {
      font-size: 14px;
      color: #CBD5E1;
    }
    .footer-bottom {
      margin-top: 32px;
      text-align: center;
      font-size: 13px;
      color: #94A3B8;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }