/* roulang page: index */
:root {
      --primary: #0A8F3C;
      --primary-hover: #08752f;
      --secondary: #1E1E1E;
      --accent: #FF5C00;
      --accent-glow: #ff7733;
      --bg-warm: #F5F4F0;
      --white: #FFFFFF;
      --text-main: #1E1E1E;
      --text-secondary: #4A4A4A;
      --text-light: #6B6B6B;
      --border-subtle: rgba(0,0,0,0.06);
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.12);
      --radius-card: 16px;
      --radius-btn: 40px;
      --transition: 0.25s ease;
      --font-system: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-system);
      background: var(--bg-warm);
      color: var(--text-main);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input {
      font-family: inherit;
      outline: none;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      z-index: 1000;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1280px;
      padding: 0 24px;
    }
    .logo {
      font-weight: 800;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      color: var(--secondary);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M13.5 2.5c-1.1 1-2.1 2.3-2.9 3.9L7 12l4.1 7.2c.8 1.5 1.8 2.8 2.9 3.8 1-.9 2-2.2 2.8-3.8L21 12l-4.2-7.2c-.8-1.5-1.8-2.8-2.8-3.8z"/></svg>') no-repeat center;
      mask-size: contain;
      -webkit-mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M13.5 2.5c-1.1 1-2.1 2.3-2.9 3.9L7 12l4.1 7.2c.8 1.5 1.8 2.8 2.9 3.8 1-.9 2-2.2 2.8-3.8L21 12l-4.2-7.2c-.8-1.5-1.8-2.8-2.8-3.8z"/></svg>') no-repeat center;
      background: var(--primary);
    }
    .nav-menu {
      display: flex;
      gap: 2.5rem;
      list-style: none;
      font-weight: 500;
      color: var(--text-secondary);
    }
    .nav-menu a {
      transition: color 0.2s;
      position: relative;
    }
    .nav-menu a:hover, .nav-menu a:focus-visible {
      color: var(--primary);
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 0.7rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      cursor: pointer;
      border: none;
      background: transparent;
      font-size: 0.95rem;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: scale(1.03);
      box-shadow: 0 6px 18px rgba(10,143,60,0.25);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
    }
    .btn-outline:hover {
      background: rgba(10,143,60,0.08);
      transform: scale(1.02);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      border: none;
    }
    .btn-accent:hover {
      background: #e85300;
      box-shadow: 0 0 16px rgba(255,92,0,0.5);
      transform: scale(1.02);
    }
    .mobile-nav-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--secondary);
    }
    /* 移动端底部导航 (隐藏默认) */
    .mobile-bottom-nav {
      display: none;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #0A8F3C 0%, #1E1E1E 85%);
      position: relative;
      overflow: hidden;
      padding-top: 72px;
    }
    .hero::before {
      content: "";
      position: absolute;
      top: -20%;
      right: -10%;
      width: 70%;
      height: 120%;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 800"><path d="M40 100 Q80 200 45 350 T60 600" stroke="rgba(255,255,255,0.08)" fill="none" stroke-width="3"/><circle cx="150" cy="200" r="70" fill="none" stroke="rgba(255,255,255,0.07)" stroke-width="2"/></svg>') no-repeat;
      background-size: contain;
      pointer-events: none;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      gap: 2rem;
      position: relative;
      z-index: 2;
    }
    .hero-content {
      flex: 1 1 50%;
      color: white;
    }
    .hero-content h1 {
      font-size: clamp(2.5rem, 5vw, 3.8rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.2;
      margin-bottom: 1.5rem;
    }
    .hero-sub {
      font-size: 1.2rem;
      opacity: 0.9;
      margin-bottom: 2rem;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1 1 45%;
      position: relative;
    }
    .hero-visual img {
      width: 100%;
      height: auto;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.4);
      object-fit: cover;
      aspect-ratio: 4/3;
      background: #2d2d2d;
    }
    /* 板块通用 */
    .section {
      padding: 80px 0;
    }
    .section-dark {
      background: var(--secondary);
      color: white;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 800;
      margin-bottom: 1rem;
      letter-spacing: -0.5px;
    }
    .section-sub {
      color: var(--text-light);
      max-width: 600px;
      margin-bottom: 3rem;
    }
    /* 核心优势 - 非三列卡片 Z型布局 */
    .advantage-row {
      display: flex;
      gap: 2.5rem;
      align-items: center;
      margin-bottom: 4rem;
      flex-wrap: wrap;
    }
    .advantage-text {
      flex: 1 1 300px;
    }
    .advantage-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 0.5rem;
    }
    .advantage-graphic {
      flex: 1 1 300px;
      background: #eae7e2;
      border-radius: 24px;
      height: 220px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--text-secondary);
    }
    /* 功能分组左右交替 */
    .feature-block {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 5rem;
    }
    .feature-img {
      flex: 1 1 48%;
      border-radius: 20px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      background: #ddd;
    }
    .feature-img img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .feature-desc {
      flex: 1 1 48%;
    }
    .feature-list {
      list-style: none;
      margin-top: 1.2rem;
    }
    .feature-list li {
      display: flex;
      align-items: center;
      gap: 0.6rem;
      margin-bottom: 0.8rem;
      font-weight: 500;
    }
    .feature-list li::before {
      content: "✓";
      color: var(--primary);
      font-weight: bold;
      font-size: 1.2rem;
    }
    /* 场景卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.8rem;
    }
    .scene-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .scene-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
    }
    .scene-card img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
      background: #ccc;
    }
    .scene-body {
      padding: 1.5rem;
    }
    /* 案例墙横向滚动 */
    .case-scroll {
      display: flex;
      gap: 1.5rem;
      overflow-x: auto;
      padding-bottom: 1rem;
      scrollbar-width: thin;
      -webkit-overflow-scrolling: touch;
    }
    .case-card {
      min-width: 260px;
      background: white;
      border-radius: 16px;
      padding: 1.5rem;
      box-shadow: var(--shadow-sm);
      flex-shrink: 0;
    }
    .case-logo {
      width: 56px;
      height: 56px;
      background: #eee;
      border-radius: 50%;
      margin-bottom: 1rem;
    }
    .case-number {
      font-size: 2.2rem;
      font-weight: 800;
      color: var(--accent);
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.08);
      padding: 0.8rem 0;
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      text-align: left;
      font-weight: 700;
      font-size: 1.1rem;
      padding: 1rem 0;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding-left: 1rem;
      border-left: 3px solid var(--primary);
      color: var(--text-secondary);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 0.5rem 1rem 1rem;
    }
    /* CTA 区块 */
    .cta-block {
      background: var(--secondary);
      padding: 5rem 0;
      text-align: center;
      color: white;
    }
    .cta-form {
      display: flex;
      gap: 1rem;
      max-width: 460px;
      margin: 2rem auto 0;
      flex-wrap: wrap;
      justify-content: center;
    }
    .cta-form input {
      flex: 1 1 220px;
      padding: 0.9rem 1.5rem;
      border-radius: 40px;
      border: none;
      background: white;
    }
    /* 页脚 */
    .footer {
      background: #151515;
      color: #bbb;
      padding: 4rem 0 2rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    .footer a:hover {
      color: var(--primary);
    }
    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .feature-block {
        flex-direction: column;
      }
      .cards-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
      }
      .mobile-nav-toggle {
        display: block;
      }
      .header-inner .btn {
        display: none;
      }
      .mobile-bottom-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        background: var(--secondary);
        justify-content: space-around;
        padding: 0.8rem 1rem;
        z-index: 999;
        border-radius: 28px 28px 0 0;
      }
      .mobile-bottom-nav a {
        color: white;
        font-size: 0.8rem;
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 4px;
      }
      .cards-grid {
        grid-template-columns: 1fr;
      }
      .hero-content h1 {
        font-size: 2.4rem;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }