/* roulang page: index */
:root {
      --green-primary: #1A7A3A;
      --green-dark: #145E2D;
      --charcoal: #1E1E1E;
      --orange-cta: #F05423;
      --orange-hover: #FF6B3D;
      --warm-white: #F9F9F9;
      --soft-green: #E8F0EB;
      --text-body: #4a4a4a;
      --text-muted: #9A9A9A;
      --border-light: rgba(0,0,0,0.05);
      --shadow-card: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08);
      --radius-lg: 12px;
      --radius-sm: 8px;
      --transition: all 0.25s ease;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--warm-white);
      color: var(--charcoal);
      line-height: 1.8;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(30,30,30,0.88);
      backdrop-filter: blur(12px);
      z-index: 1000;
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      text-decoration: none;
      color: #fff;
    }

    .logo-icon {
      width: 36px;
      height: 36px;
      background: var(--green-primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.2rem;
      color: #fff;
    }

    .logo-text {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--green-primary);
      letter-spacing: 1px;
    }

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

    .nav-link {
      color: #F9F9F9;
      text-decoration: none;
      font-weight: 500;
      transition: var(--transition);
      position: relative;
      padding-bottom: 4px;
    }

    .nav-link:hover {
      color: var(--green-primary);
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--green-primary);
      transition: width 0.2s ease;
    }

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

    .btn-cta-nav {
      background: var(--orange-cta);
      color: #fff;
      padding: 0.6rem 1.8rem;
      border-radius: 50px;
      font-weight: 700;
      letter-spacing: 1px;
      text-decoration: none;
      transition: var(--transition);
      border: none;
      cursor: pointer;
    }

    .btn-cta-nav:hover {
      background: var(--orange-hover);
      transform: translateY(-2px);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
    }

    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: #fff;
      border-radius: 4px;
    }

    /* 英雄区 */
    .hero {
      background: linear-gradient(rgba(0,0,0,0.65), rgba(0,0,0,0.7)), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 100vh;
      display: flex;
      align-items: center;
      padding-top: 80px;
      color: #fff;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }

    .hero-title {
      font-size: 3.5rem;
      font-weight: 900;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: #fff;
    }

    .hero-sub {
      font-size: 1.2rem;
      margin: 1.5rem 0 2rem;
      color: rgba(255,255,255,0.85);
    }

    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--green-primary);
      color: #fff;
      padding: 0.85rem 2.2rem;
      border-radius: var(--radius-sm);
      font-weight: 600;
      text-decoration: none;
      transition: var(--transition);
      border: none;
      cursor: pointer;
    }

    .btn-primary:hover {
      background: var(--green-dark);
    }

    .btn-ghost {
      background: transparent;
      border: 2px solid var(--green-primary);
      color: #fff;
      padding: 0.85rem 2.2rem;
      border-radius: var(--radius-sm);
      font-weight: 600;
      text-decoration: none;
      transition: var(--transition);
    }

    .btn-ghost:hover {
      background: var(--green-primary);
    }

    .data-card {
      background: rgba(255,255,255,0.1);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-lg);
      padding: 2rem;
      border: 1px solid rgba(255,255,255,0.15);
    }

    .data-number {
      font-family: "DIN Alternate", "Roboto", sans-serif;
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--orange-cta);
    }

    /* 板块通用 */
    .section {
      padding: 6rem 0;
    }

    .section-header {
      text-align: center;
      margin-bottom: 3.5rem;
    }

    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      margin-bottom: 1rem;
      color: var(--charcoal);
    }

    .section-desc {
      color: var(--text-body);
      max-width: 700px;
      margin: 0 auto;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }

    .card {
      background: #fff;
      padding: 2rem;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      border-top: 4px solid transparent;
    }

    .card:hover {
      box-shadow: var(--shadow-hover);
      border-top-color: var(--green-primary);
    }

    .card-icon {
      font-size: 2rem;
      margin-bottom: 1rem;
    }

    .grid-2 {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
    }

    .testimonial-card {
      background: var(--soft-green);
      padding: 2rem;
      border-radius: var(--radius-lg);
      display: flex;
      gap: 1.2rem;
    }

    .avatar {
      width: 60px;
      height: 60px;
      border-radius: 50%;
      background: #ccc;
    }

    blockquote {
      font-style: italic;
      color: var(--charcoal);
      margin: 0.5rem 0;
    }

    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.08);
      padding: 1.2rem 0;
    }

    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--charcoal);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-body);
    }

    .faq-answer.open {
      max-height: 160px;
      padding-top: 0.8rem;
    }

    .cta-band {
      background: var(--charcoal);
      color: #fff;
      text-align: center;
      padding: 5rem 2rem;
      border-radius: var(--radius-lg);
    }

    .footer {
      background: var(--charcoal);
      color: var(--text-muted);
      padding: 4rem 0 2rem;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }

    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .grid-3 { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .hero-title { font-size: 2.2rem; }
      .section-title { font-size: 1.8rem; }
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 520px) {
      .container { padding: 0 1.2rem; }
      .hero-buttons { flex-direction: column; }
    }