/* roulang page: index */
:root {
      --primary-deep: #1A1D23;
      --accent-orange: #E65C2B;
      --bg-warm: #F4F4F2;
      --emerald-green: #2E8B85;
      --text-body: #3A3D42;
      --white: #FFFFFF;
      --border-light: #D1D3CD;
      --card-border: #E8E9E5;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 2px 8px rgba(0,0,0,0.12), 0 8px 24px rgba(0,0,0,0.06);
      --radius-card: 8px;
      --radius-btn: 6px;
      --radius-nav: 40px;
      --max-width: 1200px;
      --section-gap: 100px;
    }

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

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      background-color: var(--bg-warm);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 40px;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    /* ---------- 浮动Dock导航 ---------- */
    .main-nav {
      position: fixed;
      top: 24px;
      left: 50%;
      transform: translateX(-50%);
      width: auto;
      max-width: 900px;
      background: rgba(26, 29, 35, 0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-radius: var(--radius-nav);
      padding: 8px 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      z-index: 100;
      box-shadow: 0 8px 20px rgba(0,0,0,0.25);
      border: 1px solid rgba(255,255,255,0.08);
      transition: all 0.2s ease;
    }

    .logo {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--white);
      letter-spacing: 0.5px;
      white-space: nowrap;
      margin-right: 2rem;
    }
    .logo span {
      color: var(--accent-orange);
    }

    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--accent-orange);
    }

    .nav-cta {
      background: var(--accent-orange);
      color: white;
      border: none;
      padding: 10px 22px;
      border-radius: 40px;
      font-weight: 600;
      font-size: 0.9rem;
      margin-left: 2rem;
      transition: background 0.2s, transform 0.2s;
      white-space: nowrap;
    }
    .nav-cta:hover {
      background: #C94E1F;
      transform: scale(1.02);
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
      line-height: 1;
      margin-left: auto;
    }

    /* 移动端导航 */
    @media (max-width: 1024px) {
      .nav-links {
        gap: 1.2rem;
      }
    }
    @media (max-width: 768px) {
      .main-nav {
        width: calc(100% - 32px);
        padding: 12px 20px;
        justify-content: space-between;
      }
      .nav-links, .nav-cta {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .mobile-menu-active .nav-links {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 80px;
        left: 0;
        width: 100%;
        background: rgba(26,29,35,0.98);
        backdrop-filter: blur(20px);
        border-radius: 24px;
        padding: 24px;
        gap: 1.5rem;
      }
      .mobile-menu-active .nav-cta {
        display: block;
        margin-left: 0;
        width: 100%;
        text-align: center;
      }
    }

    /* ---------- Hero ---------- */
    .hero {
      min-height: 85vh;
      display: flex;
      align-items: center;
      background-color: var(--bg-warm);
      background-image: radial-gradient(circle at 20% 30%, #E8E9E5 1px, transparent 1px);
      background-size: 40px 40px;
      padding-top: 120px;
      padding-bottom: 60px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-content {
      flex: 1;
    }
    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary-deep);
      line-height: 1.2;
      margin-bottom: 1.5rem;
    }
    .hero-sub {
      font-size: 20px;
      color: var(--text-body);
      max-width: 560px;
      margin-bottom: 2.5rem;
    }
    .btn-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-orange);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      transition: background 0.2s, transform 0.2s;
      box-shadow: 0 4px 10px rgba(230,92,43,0.3);
    }
    .btn-primary:hover {
      background: #C94E1F;
      transform: scale(1.02);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary-deep);
      color: var(--primary-deep);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-secondary:hover {
      background: var(--primary-deep);
      color: white;
    }
    .hero-image {
      flex: 1;
      border-radius: 20px;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.1);
      background: #d9dcd6;
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }

    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column-reverse;
      }
      .hero h1 {
        font-size: 34px;
      }
      .hero-image {
        width: 100%;
      }
    }

    /* 通用section */
    section {
      padding: var(--section-gap) 0;
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      color: var(--primary-deep);
      margin-bottom: 1rem;
      text-align: center;
    }
    .section-desc {
      text-align: center;
      color: var(--text-body);
      max-width: 700px;
      margin: 0 auto 3rem;
    }

    /* 核心优势 不对称布局 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr;
      gap: 24px;
    }
    .adv-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      border: 1px solid var(--card-border);
      box-shadow: var(--shadow-sm);
      transition: 0.2s;
    }
    .adv-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    .adv-large {
      grid-row: span 2;
    }
    .adv-icon {
      font-size: 2.2rem;
      color: var(--accent-orange);
      margin-bottom: 1rem;
    }
    .adv-card h3 {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary-deep);
      margin-bottom: 0.8rem;
    }

    @media (max-width: 768px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
      .adv-large {
        grid-row: span 1;
      }
    }

    /* 功能分组交错 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 80px;
    }
    .feature-row.reverse {
      flex-direction: row-reverse;
    }
    .feature-text {
      flex: 1;
    }
    .feature-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      background: #e0e2da;
    }
    .feature-img img {
      width: 100%;
      height: 280px;
      object-fit: cover;
    }
    .feature-list {
      list-style: none;
      margin: 1.5rem 0;
    }
    .feature-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .feature-list li::before {
      content: "●";
      color: var(--accent-orange);
      font-size: 1.2rem;
    }

    @media (max-width: 768px) {
      .feature-row, .feature-row.reverse {
        flex-direction: column;
      }
    }

    /* 场景卡片 */
    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .scenario-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--card-border);
      box-shadow: var(--shadow-sm);
      transition: 0.2s;
    }
    .scenario-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .scenario-img {
      height: 200px;
      background: #cfd2c7;
    }
    .scenario-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .scenario-content {
      padding: 20px;
    }
    .tag {
      display: inline-block;
      background: #f0f2ea;
      color: var(--primary-deep);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      margin-top: 10px;
    }

    /* 数据墙 */
    .metrics {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 2rem;
    }
    .metric-number {
      font-family: 'Inter', 'SF Pro', system-ui;
      font-size: 48px;
      font-weight: 700;
      color: var(--accent-orange);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 8px;
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      text-align: left;
      font-size: 20px;
      font-weight: 700;
      padding: 20px 0;
      display: flex;
      justify-content: space-between;
      color: var(--primary-deep);
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F9F9F7;
      padding: 0 20px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 20px;
    }

    /* 终局CTA */
    .cta-dark {
      background: var(--primary-deep);
      color: white;
      text-align: center;
      border-radius: 24px;
      padding: 60px 40px;
    }
    .cta-dark h2 {
      color: white;
    }

    footer {
      background: var(--primary-deep);
      color: rgba(255,255,255,0.7);
      padding: 40px 0;
    }
    .footer-content {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 2rem;
    }

    @media (max-width: 640px) {
      .container {
        padding: 0 20px;
      }
      .scenarios-grid {
        grid-template-columns: 1fr;
      }
    }