/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-hover: #1449B0;
      --secondary: #0EA5E9;
      --accent: #F59E0B;
      --bg: #F8FAFC;
      --card: #FFFFFF;
      --dark-bg: #1E293B;
      --text: #334155;
      --text-secondary: #64748B;
      --border: #E2E8F0;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-hover: 0 10px 25px rgba(0,0,0,0.1), 0 4px 10px rgba(0,0,0,0.05);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Inter", system-ui, sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.2s ease;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(255,255,255,0.8);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid transparent;
      transition: background 0.3s, box-shadow 0.3s, border-color 0.3s;
    }
    .header.scrolled {
      background: rgba(255,255,255,0.95);
      box-shadow: 0 2px 8px rgba(0,0,0,0.06);
      border-bottom-color: var(--border);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.5px;
    }
    .logo i {
      font-size: 2rem;
      color: var(--accent);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text);
      font-size: 0.95rem;
      position: relative;
      padding: 4px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .nav-links a.active {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--accent);
      color: #fff;
      font-weight: 600;
      padding: 10px 20px;
      border-radius: var(--radius-btn);
      font-size: 0.95rem;
      letter-spacing: 0.5px;
      box-shadow: 0 2px 4px rgba(245,158,11,0.3);
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: #e08e0a;
      transform: translateY(-1px);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text);
      transition: all 0.3s;
      display: block;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 20px;
        gap: 16px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
        border-bottom: 1px solid var(--border);
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
    }

    /* 板块通用 */
    section {
      padding: 100px 0;
      scroll-margin-top: 70px;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      text-align: center;
      margin-bottom: 50px;
    }
    .section-title h2 {
      font-size: 32px;
      font-weight: 700;
      color: #0F172A;
      margin-bottom: 12px;
    }
    .section-title .decor {
      width: 40px;
      height: 3px;
      background: var(--primary);
      margin: 8px auto 0;
      border-radius: 2px;
    }
    .section-title p {
      color: var(--text-secondary);
      max-width: 600px;
      margin: 15px auto 0;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #F0F4FE 0%, #F8FAFC 100%);
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
      width: 100%;
    }
    .hero-content {
      flex: 1 1 55%;
    }
    .hero-content h1 {
      font-size: 42px;
      font-weight: 700;
      line-height: 1.25;
      color: #0F172A;
      margin-bottom: 20px;
    }
    .hero-content .highlight {
      color: var(--primary);
      position: relative;
    }
    .hero-content p {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 30px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      transition: 0.2s;
    }
    .btn-secondary:hover {
      background: rgba(26,95,220,0.05);
    }
    .hero-image {
      flex: 1 1 45%;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      min-height: 380px;
      box-shadow: 0 20px 30px rgba(0,0,0,0.08);
    }
    @media (max-width: 768px) {
      .hero .container {
        flex-direction: column;
        text-align: center;
        gap: 40px;
      }
      .hero-content h1 {
        font-size: 32px;
      }
      .hero-content p {
        max-width: 100%;
      }
      .hero-buttons {
        justify-content: center;
      }
      .hero-image {
        width: 100%;
        min-height: 260px;
      }
    }

    /* 核心优势 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .adv-card {
      background: var(--card);
      padding: 32px 24px;
      border-radius: var(--radius-card);
      transition: all 0.25s;
      border-bottom: 3px solid transparent;
      box-shadow: var(--shadow-sm);
    }
    .adv-card:hover {
      border-bottom-color: var(--primary);
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .adv-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .adv-card h3 {
      font-size: 1.3rem;
      font-weight: 600;
      margin-bottom: 10px;
    }
    @media (max-width: 640px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 产品功能 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card);
      padding: 28px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: all 0.25s;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      width: 48px;
      height: 48px;
      background: rgba(26,95,220,0.1);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 24px;
      margin-bottom: 20px;
    }
    .feature-card h3 {
      font-weight: 600;
      margin-bottom: 8px;
    }
    .feature-link {
      color: var(--secondary);
      font-weight: 500;
      margin-top: 12px;
      display: inline-block;
      font-size: 0.9rem;
    }
    @media (max-width: 900px) {
      .features-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 600px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 应用场景 */
    .scene-row {
      display: flex;
      align-items: center;
      gap: 50px;
      margin-bottom: 80px;
    }
    .scene-row.reverse {
      flex-direction: row-reverse;
    }
    .scene-text {
      flex: 1;
    }
    .scene-text h3 {
      font-size: 24px;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .scene-text ul {
      list-style: none;
      margin-top: 12px;
    }
    .scene-text li {
      margin-bottom: 8px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .scene-text li::before {
      content: "✓";
      color: var(--primary);
      font-weight: bold;
    }
    .scene-img {
      flex: 1;
      background: #e9eef3;
      border-radius: 20px;
      min-height: 260px;
      background-size: cover;
      background-position: center;
    }
    @media (max-width: 768px) {
      .scene-row, .scene-row.reverse {
        flex-direction: column;
      }
      .scene-img {
        width: 100%;
      }
    }

    /* 成功案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      background: var(--card);
      padding: 24px;
      border-radius: var(--radius-card);
      border-left: 4px solid var(--primary);
      box-shadow: var(--shadow-sm);
      font-style: italic;
    }
    .case-card .author {
      margin-top: 16px;
      font-style: normal;
      font-weight: 600;
      color: #0F172A;
    }
    @media (max-width: 768px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
      margin-bottom: 8px;
    }
    .faq-question {
      width: 100%;
      background: white;
      padding: 18px 12px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      font-size: 16px;
      border-radius: 6px;
    }
    .faq-answer {
      padding: 0 12px 16px;
      background: #F1F5F9;
      display: none;
      font-size: 15px;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .faq-question .icon {
      font-size: 20px;
      transition: 0.2s;
    }

    /* CTA 横幅 */
    .cta-band {
      background: linear-gradient(135deg, #1A5FDC 0%, #1449B0 100%);
      color: white;
      text-align: center;
      padding: 70px 20px;
      border-radius: 0;
    }
    .cta-band h2 {
      font-size: 30px;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .cta-buttons {
      display: flex;
      gap: 16px;
      justify-content: center;
      margin-top: 24px;
      flex-wrap: wrap;
    }
    .btn-white {
      background: white;
      color: var(--primary);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
    }
    .btn-outline-white {
      border: 1.5px solid white;
      color: white;
      background: transparent;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
    }

    /* 页脚 */
    .footer {
      background: var(--dark-bg);
      color: #cbd5e1;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    .footer-brand p {
      margin-top: 12px;
      font-size: 14px;
    }
    .footer h4 {
      color: white;
      margin-bottom: 16px;
      font-weight: 600;
    }
    .footer ul {
      list-style: none;
    }
    .footer li {
      margin-bottom: 8px;
      font-size: 14px;
    }
    .social-icons {
      display: flex;
      gap: 12px;
      font-size: 20px;
    }
    .copyright {
      margin-top: 40px;
      text-align: center;
      font-size: 13px;
      border-top: 1px solid #334155;
      padding-top: 20px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 480px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }