/* roulang page: index */
:root {
      --primary: #0B1E33;
      --accent: #E94E1B;
      --bg: #F8F9FA;
      --text: #2D3748;
      --muted: #718096;
      --border-light: #E2E8F0;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
      --font-display: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-body);
      color: var(--text);
      background-color: var(--bg);
      margin: 0;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    h1, h2, h3, .display-font {
      font-family: var(--font-display);
      letter-spacing: -0.02em;
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    button, input {
      font-family: inherit;
    }

    /* 导航基础 */
    .nav-blur {
      background: rgba(255,255,255,0.75);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      transition: background 300ms ease, box-shadow 300ms ease;
    }
    .nav-scrolled {
      background: rgba(255,255,255,0.95);
      border-bottom: 1px solid var(--border-light);
    }
    .nav-link {
      font-weight: 500;
      color: #4A5568;
      transition: color 200ms;
    }
    .nav-link:hover {
      color: var(--accent);
    }
    .btn-primary {
      background-color: var(--accent);
      color: white;
      font-weight: 600;
      border-radius: 8px;
      padding: 10px 24px;
      transition: background 250ms, transform 200ms, box-shadow 200ms;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background-color: var(--accent-hover);
      transform: translateY(-1px);
      box-shadow: 0 4px 8px rgba(233,78,27,0.25);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent);
      color: var(--accent);
      font-weight: 600;
      border-radius: 8px;
      padding: 10px 24px;
      transition: background 200ms, transform 200ms;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
    }
    .btn-outline:hover {
      background-color: var(--accent-light);
      transform: translateY(-1px);
    }
    .btn-link {
      color: var(--accent);
      text-decoration: underline;
      font-weight: 500;
      background: none;
      border: none;
      cursor: pointer;
    }
    .btn-link:hover {
      text-decoration: none;
    }

    /* 卡片 */
    .card {
      background: white;
      border-radius: 12px;
      box-shadow: var(--shadow-card);
      transition: transform 250ms ease-out, box-shadow 250ms ease-out;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    /* 装饰短线条 */
    .section-dash {
      width: 40px;
      height: 4px;
      background: var(--accent);
      margin: 8px auto 24px;
      border-radius: 2px;
    }
    .section-dash.left {
      margin-left: 0;
    }

    /* 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 20px 0;
      font-weight: 500;
      color: var(--primary);
      font-size: 16px;
    }
    .faq-icon {
      color: var(--accent);
      transition: transform 350ms ease-in-out;
      font-size: 20px;
      line-height: 1;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 350ms ease-in-out, padding 350ms ease;
      background: #F7FAFC;
      padding: 0 16px;
      color: #4A5568;
      font-size: 15px;
      line-height: 1.7;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* 亮点图标hover */
    .highlight-icon-wrap {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 56px;
      height: 56px;
      border-radius: 50%;
      transition: background 200ms, transform 200ms;
      margin-bottom: 16px;
    }
    .highlight-card:hover .highlight-icon-wrap {
      background: var(--accent-light);
      transform: scale(1.1);
    }

    /* 瀑布流模拟 */
    .masonry-grid {
      column-count: 3;
      column-gap: 24px;
    }
    @media (max-width: 1023px) {
      .masonry-grid {
        column-count: 2;
      }
    }
    @media (max-width: 767px) {
      .masonry-grid {
        column-count: 1;
      }
    }
    .masonry-item {
      break-inside: avoid;
      margin-bottom: 24px;
    }

    /* 首屏动画 */
    @keyframes slideInLeft {
      0% { opacity: 0; transform: translateX(-20px); }
      100% { opacity: 1; transform: translateX(0); }
    }
    .hero-animate {
      animation: slideInLeft 0.7s ease-out forwards;
    }

    /* 移动端菜单 */
    .mobile-menu {
      display: none;
    }
    @media (max-width: 767px) {
      .desktop-nav-links {
        display: none;
      }
      .mobile-menu-btn {
        display: block;
      }
    }
    .mobile-menu.open {
      display: flex;
      flex-direction: column;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      background: white;
      padding: 24px;
      box-shadow: 0 10px 15px rgba(0,0,0,0.05);
      z-index: 40;
    }