/* roulang page: index */
/* 自定义CSS变量与全局重置 */
    :root {
      --primary-green: #1E7E34;
      --deep-black: #1B1B1B;
      --energy-orange: #F57C00;
      --bg-light: #F8FAF9;
      --card-white: #FFFFFF;
      --border-light: #E0E8E2;
      --text-body: #4A4A4A;
      --text-muted: #7A7A7A;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition-base: all 0.3s ease;
      --font-body: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
      --font-number: "DIN Alternate", "PingFang SC", sans-serif;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-base);
    }

    button, input {
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航系统 */
    #header {
      position: sticky;
      top: 0;
      background: white;
      z-index: 50;
      box-shadow: 0 2px 10px rgba(0,0,0,0.04);
      transition: var(--transition-base);
    }
    #header.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 72px;
    }
    .logo {
      font-size: 28px;
      font-weight: 700;
      color: var(--primary-green);
      letter-spacing: -0.5px;
      white-space: nowrap;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--deep-black);
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-green);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 3px;
      background: var(--primary-green);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .nav-cta {
      background: var(--energy-orange);
      color: white !important;
      padding: 10px 24px !important;
      border-radius: var(--radius-btn);
      font-weight: 600;
      box-shadow: 0 2px 8px rgba(245,124,0,0.3);
    }
    .nav-cta:hover {
      background: #E06900 !important;
      box-shadow: 0 4px 12px rgba(245,124,0,0.4);
    }
    .hamburger {
      display: none;
      font-size: 24px;
      cursor: pointer;
      color: var(--deep-black);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(8px);
      flex-direction: column;
      align-items: center;
      padding: 32px 0;
      gap: 24px;
      box-shadow: 0 10px 20px rgba(0,0,0,0.1);
      z-index: 40;
      transform: translateY(-100%);
      transition: transform 0.3s ease;
    }
    .mobile-menu.open {
      transform: translateY(0);
      display: flex;
    }
    .mobile-menu a {
      font-size: 20px;
      font-weight: 500;
      color: var(--deep-black);
    }

    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      color: var(--deep-black);
      text-align: center;
      margin-bottom: 48px;
      line-height: 1.3;
    }
    .section-subtitle {
      text-align: center;
      color: var(--text-muted);
      max-width: 700px;
      margin: -24px auto 48px;
      font-size: 16px;
    }

    /* 卡片系统 */
    .card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: var(--transition-base);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    /* 按钮规范 */
    .btn-primary {
      background: var(--energy-orange);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
      transition: var(--transition-base);
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: #E06900;
      box-shadow: 0 4px 14px rgba(245,124,0,0.4);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary-green);
      color: var(--primary-green);
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
      transition: var(--transition-base);
    }
    .btn-secondary:hover {
      background: var(--primary-green);
      color: white;
    }

    /* 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      color: var(--deep-black);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-body);
      padding-right: 40px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .faq-icon {
      color: var(--primary-green);
      font-weight: bold;
      font-size: 20px;
    }

    /* 响应式 */
    @media (max-width: 1023px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      section { padding: 60px 0; }
      .section-title { font-size: 30px; }
    }
    @media (max-width: 767px) {
      .container { padding: 0 16px; }
      .section-title { font-size: 28px; }
      .btn-primary, .btn-secondary { width: 100%; text-align: center; }
    }