/* roulang page: index */
/* 设计令牌与全局重置 */
    :root {
      --primary-deep: #0B2B26;
      --primary-gradient: linear-gradient(135deg, #0B2B26 0%, #0F3830 100%);
      --accent-signal: #00D68F;
      --accent-hover: #00BF7E;
      --alert-orange: #FF6B35;
      --bg-light: #F7F9F8;
      --bg-card: #FFFFFF;
      --bg-faq: #F0F3F2;
      --text-dark: #1A1F1E;
      --text-mid: #5A6663;
      --text-light: #8E9A96;
      --text-white: #FFFFFF;
      --border-light: #E0E6E4;
      --shadow-sm: 0 2px 12px rgba(11, 43, 38, 0.06);
      --shadow-hover: 0 8px 24px rgba(11, 43, 38, 0.10);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-head: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      --font-number: "DIN Alternate", "PingFang SC", sans-serif;
      --max-width: 1200px;
      --section-padding: 80px 20px;
    }

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

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

    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }

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

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

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: all 0.2s ease;
      cursor: pointer;
      border: none;
      font-family: var(--font-body);
      letter-spacing: 0.3px;
    }

    .btn-primary {
      background: var(--accent-signal);
      color: var(--primary-deep);
      padding: 14px 32px;
      font-size: 1rem;
      box-shadow: 0 2px 8px rgba(0, 214, 143, 0.25);
    }

    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.03);
      box-shadow: 0 4px 14px rgba(0, 214, 143, 0.3);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-signal);
      color: var(--accent-signal);
      padding: 12px 30px;
    }

    .btn-outline:hover {
      background: rgba(0, 214, 143, 0.08);
      border-color: var(--accent-hover);
      color: var(--accent-hover);
    }

    .btn-white {
      background: var(--text-white);
      color: var(--primary-deep);
      padding: 14px 32px;
      font-weight: 600;
    }

    .btn-white:hover {
      background: #F0F3F2;
      transform: scale(1.02);
    }

    .btn-large {
      padding: 18px 48px;
      font-size: 1.25rem;
    }

    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(247, 249, 248, 0.92);
      backdrop-filter: blur(12px);
      z-index: 1000;
      border-bottom: 1px solid transparent;
      transition: all 0.3s ease;
    }

    .site-header.scrolled {
      background: rgba(247, 249, 248, 0.98);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-light);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
      height: 70px;
    }

    .logo {
      font-family: var(--font-head);
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary-deep);
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo span {
      color: var(--accent-signal);
      font-weight: 700;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-menu a {
      font-weight: 500;
      color: var(--text-mid);
      padding: 8px 0;
      position: relative;
      font-size: 0.95rem;
      transition: color 0.2s;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--accent-signal);
    }

    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-signal);
      transition: width 0.25s ease;
    }

    .nav-menu a:hover::after {
      width: 100%;
    }

    .nav-cta {
      margin-left: 16px;
    }

    /* 移动端菜单 */
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--primary-deep);
      cursor: pointer;
    }

    @media (max-width: 1024px) {
      .nav-menu {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px 0;
        box-shadow: var(--shadow-sm);
        gap: 16px;
        align-items: flex-start;
        padding-left: 24px;
      }
      .nav-menu.active {
        display: flex;
      }
      .menu-toggle {
        display: block;
      }
      .nav-cta {
        margin-left: 0;
        margin-top: 8px;
      }
    }

    /* 区块通用 */
    section {
      padding: var(--section-padding);
    }

    .section-title {
      font-family: var(--font-head);
      font-size: 2rem;
      font-weight: 600;
      line-height: 1.3;
      margin-bottom: 16px;
      color: var(--primary-deep);
      text-align: center;
    }

    .section-subtitle {
      color: var(--text-mid);
      font-size: 1.1rem;
      text-align: center;
      max-width: 700px;
      margin: 0 auto 48px;
    }

    /* Hero */
    .hero {
      background: var(--primary-gradient);
      padding: 120px 20px 80px;
      color: white;
      position: relative;
      overflow: hidden;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      max-width: var(--max-width);
      margin: 0 auto;
    }

    .hero-content {
      flex: 1;
    }

    .badge {
      background: rgba(0, 214, 143, 0.15);
      color: var(--accent-signal);
      padding: 6px 16px;
      border-radius: 20px;
      font-size: 0.85rem;
      font-weight: 500;
      display: inline-block;
      margin-bottom: 20px;
    }

    .hero h1 {
      font-family: var(--font-head);
      font-size: 2.8rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
    }

    .hero p {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      align-items: center;
    }

    .hero-image {
      flex: 0.9;
      text-align: right;
    }

    .hero-image img {
      max-height: 420px;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    }

    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-image {
        text-align: center;
      }
    }

    /* 痛点卡片 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 20px;
    }

    .pain-card {
      background: var(--bg-card);
      padding: 28px;
      border-radius: var(--radius-card);
      border-left: 4px solid var(--accent-signal);
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
    }

    .pain-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    /* 解决方案网格 */
    .solution-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }

    .solution-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
    }

    .solution-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }

    .solution-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }

    .solution-content {
      padding: 24px;
    }

    /* 优势数字 */
    .adv-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }

    .adv-item .number {
      font-family: var(--font-number);
      font-size: 3rem;
      color: var(--accent-signal);
      font-weight: 700;
    }

    /* 流程 */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      flex-wrap: wrap;
      gap: 24px;
    }

    .step {
      flex: 1;
      text-align: center;
    }

    .step-circle {
      width: 48px;
      height: 48px;
      background: var(--accent-signal);
      border-radius: 50%;
      color: white;
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px;
      font-size: 1.2rem;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    details {
      background: var(--bg-faq);
      border-radius: var(--radius-card);
      padding: 18px 24px;
      margin-bottom: 12px;
      transition: 0.3s;
    }

    summary {
      font-weight: 600;
      font-size: 1.1rem;
      cursor: pointer;
      list-style: none;
      display: flex;
      justify-content: space-between;
    }

    /* CTA 深色区 */
    .cta-dark {
      background: var(--primary-gradient);
      text-align: center;
      color: white;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
      color: #ccc;
    }

    @media (max-width: 768px) {
      .pain-grid, .adv-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .solution-grid {
        grid-template-columns: 1fr;
      }
    }