/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent-gold: #D4AF37;
      --accent-gold-hover: #b8941f;
      --bg-warm: #F5F3EE;
      --surface-dark: #1A1F3A;
      --surface-dark-hover: #252b4a;
      --text-main: #1C1C1C;
      --text-muted: #5A5A5A;
      --text-light: #B0B3C1;
      --danger: #FF4D4D;
      --danger-bg: #FEF2F2;
      --white: #ffffff;
      --border-light: rgba(10, 14, 39, 0.08);
      --shadow-card: 0 4px 24px rgba(10,14,39,0.06);
      --shadow-card-hover: 0 12px 32px rgba(10,14,39,0.12);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --radius-pill: 40px;
      --font-heading: 'PingFang SC', 'Noto Sans SC', 'Inter', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
      --font-body: 'PingFang SC', 'Noto Sans SC', 'Inter', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
      --transition-smooth: 0.25s cubic-bezier(0.2, 0.0, 0, 1.0);
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
      font-family: var(--font-body);
      background-color: var(--bg-warm);
      color: var(--text-main);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    a { text-decoration: none; color: inherit; }
    img { max-width: 100%; height: auto; display: block; }
    button, input { font-family: inherit; }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background var(--transition-smooth), backdrop-filter var(--transition-smooth), box-shadow var(--transition-smooth);
      background: transparent;
      backdrop-filter: none;
      box-shadow: none;
    }
    .site-header.scrolled {
      background: rgba(245, 243, 238, 0.92);
      backdrop-filter: blur(8px);
      box-shadow: 0 1px 0 var(--border-light);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 800;
      font-size: 1.6rem;
      color: var(--primary);
      letter-spacing: -0.5px;
    }
    .logo i { color: var(--accent-gold); font-size: 1.8rem; }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 40px;
      list-style: none;
    }
    .nav-menu a {
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 4px 0;
      transition: color var(--transition-smooth);
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-gold);
      transition: width var(--transition-smooth);
    }
    .nav-menu a:hover { color: var(--accent-gold); }
    .nav-menu a:hover::after { width: 100%; }
    .btn-primary {
      background: var(--accent-gold);
      color: #0A0E27;
      font-weight: 700;
      padding: 12px 28px;
      border-radius: var(--radius-pill);
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: background var(--transition-smooth), transform var(--transition-smooth), box-shadow var(--transition-smooth);
      border: none;
      cursor: pointer;
      font-size: 0.95rem;
    }
    .btn-primary:hover {
      background: var(--accent-gold-hover);
      transform: scale(1.02);
      box-shadow: 0 8px 18px rgba(212, 175, 55, 0.3);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--text-main);
      color: var(--text-main);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-pill);
      transition: all var(--transition-smooth);
      cursor: pointer;
    }
    .btn-outline:hover {
      background: var(--text-main);
      color: var(--bg-warm);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      transition: var(--transition-smooth);
    }
    /* Hero */
    .hero-section {
      padding: 140px 0 80px;
      background: var(--bg-warm);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 55% 45%;
      gap: 60px;
      align-items: center;
    }
    .hero-title {
      font-family: var(--font-heading);
      font-size: clamp(40px, 6vw, 56px);
      font-weight: 800;
      line-height: 1.1;
      color: var(--primary);
      margin-bottom: 24px;
    }
    .hero-title .highlight {
      color: var(--accent-gold);
      display: inline-block;
    }
    .hero-sub {
      font-size: 1.15rem;
      color: var(--text-muted);
      max-width: 480px;
      margin-bottom: 40px;
      line-height: 1.6;
    }
    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      margin-bottom: 48px;
    }
    .trust-bar {
      display: flex;
      gap: 32px;
      color: var(--text-muted);
      font-size: 0.9rem;
      font-weight: 500;
    }
    .trust-bar i { color: var(--accent-gold); margin-right: 6px; }
    .hero-image-wrapper {
      position: relative;
      transform: rotate(-2deg);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: 0 30px 50px rgba(10,14,39,0.2);
    }
    /* 板块通用 */
    .section {
      padding: 80px 0;
    }
    .section-title {
      font-family: var(--font-heading);
      font-size: clamp(32px, 5vw, 40px);
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 16px;
      line-height: 1.2;
    }
    .section-desc {
      color: var(--text-muted);
      font-size: 1.1rem;
      max-width: 600px;
      margin-bottom: 48px;
    }
    /* 优势网格 (非对称) */
    .advantage-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .advantage-grid .card-large {
      grid-row: span 2;
      background: var(--surface-dark);
      color: white;
      border-radius: var(--radius-lg);
      padding: 40px;
      display: flex;
      flex-direction: column;
      justify-content: center;
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }
    .card-large:hover { transform: translateY(-6px); box-shadow: var(--shadow-card-hover); }
    .card-large i { font-size: 48px; color: var(--accent-gold); margin-bottom: 24px; }
    .card-large h3 { font-size: 1.8rem; margin-bottom: 16px; }
    .small-cards {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .small-card {
      background: var(--surface-dark);
      color: white;
      border-radius: var(--radius-md);
      padding: 28px;
      transition: transform 0.3s, box-shadow 0.3s;
    }
    .small-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-card-hover); }
    .small-card i { font-size: 36px; color: var(--accent-gold); margin-bottom: 20px; }
    .small-card h4 { font-size: 1.25rem; margin-bottom: 10px; }
    /* 下载区瀑布流 */
    .download-layout {
      display: flex;
      gap: 40px;
    }
    .tab-vertical {
      display: flex;
      flex-direction: column;
      gap: 12px;
      min-width: 180px;
    }
    .tab-vertical button {
      background: transparent;
      border: 1px solid var(--border-light);
      color: var(--text-main);
      font-weight: 600;
      padding: 14px 20px;
      border-radius: var(--radius-sm);
      text-align: left;
      transition: var(--transition-smooth);
      cursor: pointer;
      font-size: 1rem;
    }
    .tab-vertical button.active, .tab-vertical button:hover {
      background: var(--accent-gold);
      border-color: var(--accent-gold);
      color: #0A0E27;
    }
    .download-cards {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
      gap: 24px;
      flex: 1;
    }
    .download-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
    }
    .download-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-card-hover); }
    .download-card img {
      aspect-ratio: 16/9;
      object-fit: cover;
      background: #eaeaea;
    }
    .download-info { padding: 20px; }
    .version-tag {
      background: #f0f0f0;
      color: var(--text-main);
      font-weight: 600;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      display: inline-block;
      margin-bottom: 8px;
    }
    .download-info h4 { margin: 12px 0 4px; }
    .update-date { color: var(--text-muted); font-size: 0.9rem; }
    /* 对比布局 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr auto 1fr;
      gap: 32px;
      align-items: center;
    }
    .compare-card {
      padding: 40px;
      border-radius: var(--radius-lg);
    }
    .compare-left {
      background: #fff5f5;
      border: 1px solid #fecaca;
    }
    .compare-right {
      background: var(--surface-dark);
      color: white;
    }
    .compare-left h3 { color: var(--danger); }
    .compare-right h3 { color: var(--accent-gold); }
    .compare-list { list-style: none; margin-top: 24px; }
    .compare-list li { margin-bottom: 16px; display: flex; align-items: center; gap: 10px; }
    .compare-left li i { color: var(--danger); }
    .compare-right li i { color: var(--accent-gold); }
    .vs-badge {
      background: var(--accent-gold);
      color: #0A0E27;
      font-weight: 800;
      width: 60px;
      height: 60px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
    }
    /* FAQ 双列手风琴 */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .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: 700;
      font-size: 1.1rem;
      cursor: pointer;
      gap: 16px;
    }
    .faq-question i { transition: transform 0.2s; color: var(--accent-gold); }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, opacity 0.3s;
      opacity: 0;
      color: var(--text-muted);
      padding-right: 20px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      opacity: 1;
      margin-top: 12px;
    }
    .faq-item.open .faq-question i { transform: rotate(180deg); }
    /* CTA 深色区 */
    .cta-dark {
      background: var(--primary);
      background-image: radial-gradient(circle at 20% 30%, #1a1f3a 0%, #0a0e27 90%);
      color: white;
      text-align: center;
      padding: 100px 0;
    }
    .cta-dark h2 { color: white; font-size: 2.8rem; margin-bottom: 16px; }
    .cta-dark p { color: #b0b3c1; margin-bottom: 32px; }
    .small-note { font-size: 0.9rem; color: #8a8fa0; margin-top: 12px; }
    /* 页脚 */
    .footer {
      background: var(--primary);
      color: var(--text-light);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer h5 { color: white; font-weight: 600; margin-bottom: 16px; }
    .footer a { color: var(--text-light); display: block; margin-bottom: 10px; transition: color 0.2s; }
    .footer a:hover { color: var(--accent-gold); }
    .copyright {
      text-align: center;
      margin-top: 48px;
      padding-top: 24px;
      border-top: 1px solid rgba(255,255,255,0.1);
      font-size: 0.85rem;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .compare-grid { grid-template-columns: 1fr; }
      .vs-badge { margin: 16px auto; }
      .faq-grid { grid-template-columns: 1fr; }
      .download-layout { flex-direction: column; }
      .tab-vertical { flex-direction: row; flex-wrap: wrap; min-width: auto; }
    }
    @media (max-width: 768px) {
      .container { padding: 0 20px; }
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .mobile-menu {
        position: fixed; top: 0; left: 0; width: 100%; height: 100vh;
        background: var(--bg-warm); display: flex; flex-direction: column;
        align-items: center; justify-content: center; gap: 32px; z-index: 999;
        transform: translateX(100%); transition: transform 0.3s;
      }
      .mobile-menu.active { transform: translateX(0); }
      .advantage-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .hero-image-wrapper { transform: rotate(0); }
    }