/* roulang page: index */
:root {
      --primary-deep: #1A2B4C;
      --accent-orange: #F15A24;
      --bg-cool: #F7F9FC;
      --white: #FFFFFF;
      --text-body: #2D3748;
      --text-muted: #718096;
      --success-green: #10B981;
      --border-light: #E2E8F0;
      --card-shadow: 0 4px 20px rgba(0,0,0,0.06);
      --card-hover-shadow: 0 12px 30px rgba(0,0,0,0.12);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-pill: 20px;
      --transition: 0.3s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Inter", system-ui, sans-serif;
      --max-width: 1280px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-cool);
      color: var(--text-body);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* 导航 */
    .nav {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(12px);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      padding: 0 24px;
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--max-width);
      margin: 0 auto;
      height: 72px;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 800;
      color: var(--primary-deep);
      text-decoration: none;
      letter-spacing: -0.3px;
    }
    .logo span {
      color: var(--accent-orange);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      text-decoration: none;
      color: var(--text-body);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 8px 4px;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-orange);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 24px;
      height: 4px;
      background: var(--accent-orange);
      border-radius: 4px;
    }
    .btn-nav {
      background: var(--accent-orange);
      color: white !important;
      padding: 10px 22px !important;
      border-radius: var(--radius-sm);
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(241,90,36,0.25);
    }
    .btn-nav:hover {
      background: #d94a1a;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: var(--primary-deep);
      border-radius: 2px;
      transition: 0.2s;
    }
    .mobile-menu {
      display: none;
    }

    /* 板块间距 */
    section {
      padding: 90px 0;
    }
    .hero-section {
      padding: 70px 0 100px;
      background: linear-gradient(135deg, rgba(26,43,76,0.75) 0%, rgba(26,43,76,0.85) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      color: white;
    }

    h1 {
      font-size: 3rem;
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: -0.6px;
      color: var(--primary-deep);
    }
    h2 {
      font-size: 2rem;
      font-weight: 700;
      color: var(--primary-deep);
      margin-bottom: 1.2rem;
    }
    .text-white h1, .text-white h2 {
      color: white;
    }
    .btn {
      display: inline-block;
      font-weight: 600;
      padding: 14px 34px;
      border-radius: var(--radius-sm);
      text-decoration: none;
      transition: var(--transition);
      cursor: pointer;
      border: none;
      font-size: 1rem;
    }
    .btn-primary {
      background: var(--accent-orange);
      color: white;
      box-shadow: 0 6px 18px rgba(241,90,36,0.4);
    }
    .btn-primary:hover {
      background: #d94a1a;
      transform: translateY(-2px);
      box-shadow: 0 10px 24px rgba(241,90,36,0.5);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary-deep);
      color: var(--primary-deep);
      background: white;
    }
    .btn-secondary:hover {
      background: var(--primary-deep);
      color: white;
    }
    .btn-white {
      background: white;
      color: var(--primary-deep);
      font-weight: 700;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--card-hover-shadow);
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--accent-orange);
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      color: var(--primary-deep);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: #4A5568;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    footer {
      background: var(--primary-deep);
      color: #CBD5E0;
      padding: 60px 0 30px;
    }
    footer a {
      color: #CBD5E0;
      text-decoration: none;
    }
    footer a:hover {
      color: var(--accent-orange);
    }

    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2,1fr); }
      .grid-3 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      h1 { font-size: 2.2rem; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu {
        position: fixed; top:0; left:0; width:100%; height:100%;
        background: var(--primary-deep); flex-direction: column;
        justify-content: center; align-items: center; gap:2rem;
        z-index: 100; display: none;
      }
      .mobile-menu a { color: white; font-size: 1.5rem; }
      .grid-3, .grid-4 { grid-template-columns: 1fr; }
      section { padding: 60px 0; }
    }