/* roulang page: index */
:root {
      --primary-deep: #0B3D3A;
      --accent-orange: #F15A24;
      --accent-orange-dark: #D94A1A;
      --neon-lime: #C7F950;
      --bg-warm: #F7F5F0;
      --bg-dark: #1A1A1A;
      --text-primary: #1A1A1A;
      --text-secondary: #5C5C5C;
      --white: #FFFFFF;
      --light-gray: #FAFAFA;
      --border-light: rgba(0,0,0,0.04);
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 30px rgba(0,0,0,0.08);
      --shadow-nav: 0 2px 20px rgba(0,0,0,0.06);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', sans-serif;
      --font-number: 'DIN Alternate', 'PingFang SC', sans-serif;
      --transition-smooth: all 0.25s ease;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--bg-warm);
      color: var(--text-primary);
      line-height: 1.75;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    h1, h2, h3, h4 {
      font-family: var(--font-title);
      font-weight: 700;
    }

    h1 {
      font-size: 48px;
      line-height: 56px;
      letter-spacing: -0.5px;
    }

    h2 {
      font-size: 36px;
      line-height: 44px;
      letter-spacing: 0;
    }

    h3 {
      font-size: 22px;
      line-height: 30px;
      font-weight: 600;
    }

    h4 {
      font-size: 16px;
      line-height: 24px;
      font-weight: 600;
    }

    .text-number {
      font-family: var(--font-number);
      font-weight: 700;
    }

    .btn-primary {
      background-color: var(--accent-orange);
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      border: none;
      cursor: pointer;
      transition: var(--transition-smooth);
      display: inline-block;
      text-decoration: none;
      text-align: center;
    }

    .btn-primary:hover {
      background-color: var(--accent-orange-dark);
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(241,90,36,0.3);
    }

    .btn-outline {
      background: transparent;
      color: var(--primary-deep);
      border: 2px solid var(--primary-deep);
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition-smooth);
      display: inline-block;
      text-decoration: none;
      text-align: center;
    }

    .btn-outline:hover {
      background-color: rgba(11,61,58,0.1);
      transform: translateY(-2px);
    }

    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
      overflow: hidden;
    }

    .card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }

    .section-padding {
      padding: 120px 0;
    }

    @media (max-width: 1024px) {
      .section-padding {
        padding: 80px 0;
      }
    }

    @media (max-width: 768px) {
      h1 {
        font-size: 32px;
        line-height: 40px;
      }
      h2 {
        font-size: 26px;
        line-height: 34px;
      }
      h3 {
        font-size: 20px;
        line-height: 28px;
      }
      .section-padding {
        padding: 60px 0;
      }
      .container {
        padding: 0 20px;
      }
    }

    /* 导航 */
    .main-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: white;
      z-index: 50;
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(0,0,0,0.05);
      transition: var(--transition-smooth);
    }

    .main-nav.scrolled {
      box-shadow: var(--shadow-nav);
    }

    .nav-logo {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 24px;
      color: var(--primary-deep);
      text-decoration: none;
      letter-spacing: 0.5px;
    }

    .nav-menu {
      display: flex;
      gap: 32px;
      list-style: none;
      margin-left: auto;
      margin-right: 24px;
    }

    .nav-menu a {
      text-decoration: none;
      color: var(--text-primary);
      font-weight: 500;
      font-size: 16px;
      transition: color 0.2s;
    }

    .nav-menu a:hover {
      color: var(--accent-orange);
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--primary-deep);
      cursor: pointer;
    }

    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        height: calc(100vh - 72px);
        background: white;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 40px;
        transform: translateY(-100%);
        opacity: 0;
        transition: transform 0.3s ease, opacity 0.3s ease;
        margin: 0;
        z-index: 49;
      }
      .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
      }
      .nav-menu a {
        font-size: 24px;
      }
      .hamburger {
        display: block;
        margin-left: auto;
      }
      .nav-cta {
        display: none;
      }
    }

    /* hero 动态背景 */
    .hero-graphic {
      position: relative;
      width: 100%;
      height: 100%;
      min-height: 400px;
      background: radial-gradient(circle at 30% 40%, rgba(11,61,58,0.1) 0%, transparent 60%);
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .arc {
      position: absolute;
      border-radius: 50%;
      border: 2px solid var(--primary-deep);
      opacity: 0.2;
      animation: floatArc 6s infinite alternate ease-in-out;
    }

    @keyframes floatArc {
      0% { transform: translateY(0) scale(1); }
      100% { transform: translateY(-8px) scale(1.02); }
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.08);
      background: var(--bg-warm);
      transition: background 0.3s;
    }
    .faq-item.active {
      background: white;
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      color: var(--primary-deep);
      font-size: 18px;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      color: var(--text-secondary);
      padding: 0 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }
    .faq-icon {
      transition: transform 0.3s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* 数字递增 */
    .count-up {
      font-family: var(--font-number);
      font-size: 48px;
      color: var(--neon-lime);
    }

    /* 瀑布流 */
    .masonry {
      column-count: 3;
      column-gap: 24px;
    }
    @media (max-width: 992px) {
      .masonry {
        column-count: 2;
      }
    }
    @media (max-width: 768px) {
      .masonry {
        column-count: 1;
      }
    }
    .masonry-item {
      break-inside: avoid;
      margin-bottom: 24px;
      display: inline-block;
      width: 100%;
    }

    /* 渐现动画 */
    .fade-up {
      opacity: 0;
      transform: translateY(30px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }