/* roulang page: index */
:root {
      --primary: #0D7377;
      --primary-hover: #0A5C5F;
      --accent: #F9A826;
      --bg-light: #F7F9FC;
      --white: #FFFFFF;
      --dark-bg: #1A3636;
      --text-main: #1A1A1A;
      --text-body: #4A4A4A;
      --text-muted: #7A7A7A;
      --border-light: #E8ECF1;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.08);
      --radius-md: 12px;
      --radius-btn: 8px;
      --radius-sm: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.8;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    /* 导航卡片化面板 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 0.75rem 0;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1200px;
      padding: 0 1.5rem;
    }
    .logo {
      font-weight: 700;
      font-size: 1.6rem;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 0.3rem;
    }
    .logo span {
      background: var(--primary);
      color: white;
      padding: 0.2rem 0.5rem;
      border-radius: 6px;
      font-size: 0.9rem;
      margin-left: 0.2rem;
    }
    .nav-links {
      display: flex;
      gap: 0.5rem;
      align-items: center;
    }
    .nav-links a {
      padding: 0.5rem 1rem;
      border-radius: 20px;
      font-weight: 500;
      color: var(--text-main);
      transition: background 0.2s, color 0.2s;
      font-size: 0.95rem;
    }
    .nav-links a:hover {
      background: rgba(13, 115, 119, 0.08);
      color: var(--primary);
    }
    .nav-cta {
      background: var(--primary);
      color: white !important;
      padding: 0.55rem 1.4rem !important;
      border-radius: 20px;
      font-weight: 600;
      margin-left: 0.5rem;
    }
    .nav-cta:hover {
      background: var(--primary-hover) !important;
      color: white !important;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2.5px;
      background: var(--primary);
      border-radius: 3px;
      transition: 0.2s;
    }
    /* 移动端菜单 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 70px;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(16px);
      padding: 1.5rem;
      flex-direction: column;
      gap: 0.8rem;
      box-shadow: 0 20px 30px rgba(0,0,0,0.05);
      z-index: 40;
    }
    .mobile-menu a {
      display: block;
      padding: 1rem;
      background: white;
      border-radius: var(--radius-md);
      font-weight: 500;
      color: var(--text-main);
      box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    }
    .section {
      padding: 5rem 0;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 1.5rem;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 50px;
      height: 4px;
      background: var(--primary);
      border-radius: 2px;
    }
    .text-center .section-title::after {
      left: 50%;
      transform: translateX(-50%);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 0.85rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
      transition: 0.2s;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      background: transparent;
      transition: 0.2s;
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .card {
      background: var(--white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-3px);
    }
    footer {
      background: var(--dark-bg);
      color: #ccc;
      padding: 3rem 0 1.5rem;
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .section { padding: 3.5rem 0; }
      .section-title { font-size: 2rem; }
    }