/* roulang page: index */
:root {
      --deep-pine: #0A2E1F;
      --pine-gradient: linear-gradient(135deg, #0A2E1F 0%, #0F3D2A 100%);
      --moss-light: #E8F0E3;
      --bronze-gold: #C49A3C;
      --bronze-hover: #A67F2E;
      --text-primary: #1A1A1A;
      --text-secondary: #4A4A4A;
      --text-on-dark: #FFFFFF;
      --white: #FFFFFF;
      --card-bg: #FAFAF8;
      --border-light: #DDE5D8;
      --shadow-sm: 0 2px 12px rgba(10,46,31,0.06);
      --shadow-md: 0 8px 24px rgba(10,46,31,0.12);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-sm: 12px;
      --transition-smooth: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --font-number: "Inter", "SF Pro Text", system-ui, sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: var(--font-sans);
      color: var(--text-primary);
      background-color: var(--moss-light);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    .section {
      padding-top: 7.5rem;
      padding-bottom: 7.5rem;
    }
    @media (max-width: 767px) {
      .section {
        padding-top: 5rem;
        padding-bottom: 5rem;
      }
      html {
        font-size: 15px;
      }
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: var(--transition-smooth);
    }
    .btn-primary {
      background-color: var(--bronze-gold);
      color: white;
      padding: 0.875rem 2rem;
      font-size: 1rem;
      box-shadow: 0 0 0 rgba(196,154,60,0);
    }
    .btn-primary:hover {
      background-color: var(--bronze-hover);
      box-shadow: 0 0 20px rgba(196,154,60,0.5);
      transform: translateY(-2px);
      color: white;
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--deep-pine);
      color: var(--deep-pine);
      padding: 0.875rem 2rem;
    }
    .btn-outline:hover {
      background-color: var(--deep-pine);
      color: white;
      border-color: var(--deep-pine);
    }
    .btn-lg {
      padding: 1rem 2.5rem;
      font-size: 1.1rem;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.25;
      color: var(--deep-pine);
    }
    h1 {
      font-size: 3rem;
      letter-spacing: -0.5px;
    }
    h2 {
      font-size: 2.25rem;
      margin-bottom: 1rem;
    }
    h3 {
      font-size: 1.5rem;
    }
    .text-bronze {
      color: var(--bronze-gold);
    }
    .text-muted {
      color: var(--text-secondary);
    }
    .bg-pine {
      background-color: var(--deep-pine);
    }
    .bg-moss {
      background-color: var(--moss-light);
    }
    /* 导航 */
    .navbar {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(10,46,31,0.05);
      box-shadow: 0 4px 12px rgba(0,0,0,0.02);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 0.4rem;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--deep-pine);
      letter-spacing: 1px;
    }
    .logo i {
      font-size: 2rem;
      color: var(--bronze-gold);
    }
    .nav-menu {
      display: flex;
      gap: 2.2rem;
      align-items: center;
      list-style: none;
    }
    .nav-menu a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-primary);
      position: relative;
      padding-bottom: 4px;
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background-color: var(--bronze-gold);
      transition: width 0.25s ease;
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      width: 28px;
      height: 20px;
      justify-content: center;
      align-items: flex-end;
    }
    .hamburger span {
      display: block;
      height: 2.5px;
      background: var(--deep-pine);
      border-radius: 4px;
      transition: 0.25s ease;
    }
    .hamburger span:nth-child(1) { width: 24px; }
    .hamburger span:nth-child(2) { width: 18px; }
    .hamburger span:nth-child(3) { width: 24px; }
    @media (max-width: 767px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: var(--deep-pine);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 2.8rem;
        transition: right 0.35s ease;
        box-shadow: -8px 0 24px rgba(0,0,0,0.15);
      }
      .nav-menu.active {
        right: 0;
      }
      .nav-menu a {
        color: white;
        font-size: 1.3rem;
      }
      .hamburger {
        display: flex;
        z-index: 110;
      }
    }
    /* Hero */
    .hero {
      background: var(--pine-gradient);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero-content {
      color: white;
      max-width: 700px;
      position: relative;
      z-index: 2;
    }
    .hero h1 {
      color: white;
      font-size: 3.4rem;
      margin-bottom: 1.5rem;
    }
    .hero .sub {
      font-size: 1.2rem;
      opacity: 0.9;
      margin-bottom: 2.5rem;
    }
    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    .hero-visual {
      position: absolute;
      right: 0;
      bottom: 0;
      width: 50%;
      height: 100%;
      background: url('/assets/images/backpic/back-1.webp') no-repeat center/cover;
      opacity: 0.35;
      mask-image: linear-gradient(to left, black 30%, transparent 90%);
      -webkit-mask-image: linear-gradient(to left, black 30%, transparent 90%);
    }
    @media (max-width: 767px) {
      .hero {
        text-align: center;
      }
      .hero h1 {
        font-size: 2.3rem;
      }
      .hero-visual {
        width: 100%;
        opacity: 0.2;
      }
      .hero-buttons {
        justify-content: center;
      }
    }
    /* 卡片通用 */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      transition: var(--transition-smooth);
      border: 1px solid var(--border-light);
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    /* 核心优势 非对称网格 */
    .advantage-grid {
      display: grid;
      grid-template-columns: 1.3fr 1fr;
      gap: 1.5rem;
    }
    .advantage-main {
      grid-row: span 2;
      background: var(--white);
    }
    .advantage-sub {
      background: var(--white);
    }
    @media (max-width: 767px) {
      .advantage-grid {
        grid-template-columns: 1fr;
      }
      .advantage-main {
        grid-row: span 1;
      }
    }
    /* 功能交替 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 5rem;
    }
    .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);
    }
    .feature-img img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    @media (max-width: 767px) {
      .feature-row, .feature-row.reverse {
        flex-direction: column;
        gap: 2rem;
      }
    }
    /* 场景卡片 */
    .scene-card {
      background: rgba(255,255,255,0.12);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-sm);
      padding: 1.5rem;
      color: white;
      border: 1px solid rgba(255,255,255,0.2);
    }
    /* 案例横滚 */
    .case-scroll {
      display: flex;
      gap: 1.5rem;
      overflow-x: auto;
      padding-bottom: 1rem;
      scrollbar-width: thin;
      scrollbar-color: var(--bronze-gold) transparent;
    }
    .case-scroll::-webkit-scrollbar {
      height: 6px;
    }
    .case-scroll::-webkit-scrollbar-thumb {
      background: var(--bronze-gold);
      border-radius: 8px;
    }
    .case-card {
      min-width: 300px;
      flex: 0 0 auto;
      background: white;
    }
    @media (max-width: 767px) {
      .case-scroll {
        flex-direction: column;
        overflow-x: visible;
      }
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.2rem 0;
    }
    .faq-question {
      width: 100%;
      background: none;
      text-align: left;
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--deep-pine);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 0.8rem;
    }
    /* CTA */
    .cta-band {
      background: var(--pine-gradient);
      text-align: center;
      color: white;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    @media (max-width: 767px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }