/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent-cyan: #00F0FF;
      --accent-red: #FF2D55;
      --deep-blue: #1A1F3A;
      --bg-light: #F5F6FA;
      --text-dark: #1A1A2E;
      --text-muted: #6B7280;
      --card-bg: #FFFFFF;
      --border-light: #E5E7EB;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --shadow-card: 0 4px 20px rgba(10,14,39,0.06);
      --shadow-hover: 0 8px 30px rgba(10,14,39,0.12);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-mono: "Inter", "SF Pro Display", -apple-system, sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      font-size: 16px;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input, textarea {
      font-family: inherit;
      font-size: inherit;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .site-header {
      background-color: rgba(26,31,58,0.92);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      position: sticky;
      top: 0;
      z-index: 1000;
      transition: box-shadow 0.25s ease;
      box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    }
    .site-header.scrolled {
      box-shadow: 0 8px 24px rgba(0,0,0,0.25);
      background-color: rgba(26,31,58,0.98);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 1.6rem;
      font-weight: 700;
      color: #fff;
      letter-spacing: 0.5px;
    }
    .logo i {
      color: var(--accent-cyan);
      font-size: 1.8rem;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: rgba(255,255,255,0.8);
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover {
      color: var(--accent-cyan);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.2s;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-nav {
      background: linear-gradient(135deg, #00F0FF 0%, #0A0E27 100%);
      color: white;
      border: none;
      padding: 10px 24px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 0.9rem;
      cursor: pointer;
      transition: filter 0.2s, box-shadow 0.2s;
      margin-left: 18px;
    }
    .btn-nav:hover {
      filter: brightness(1.15);
      box-shadow: 0 0 16px rgba(0,240,255,0.4);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: white;
      border-radius: 2px;
      transition: 0.2s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: #1A1F3A;
      z-index: 999;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 32px;
      transform: translateX(100%);
      transition: transform 0.35s ease;
    }
    .mobile-menu.active {
      display: flex;
      transform: translateX(0);
    }
    .mobile-menu a {
      color: white;
      font-size: 1.5rem;
      font-weight: 600;
    }
    .mobile-close {
      position: absolute;
      top: 24px;
      right: 24px;
      background: none;
      border: none;
      color: white;
      font-size: 2rem;
      cursor: pointer;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0A0E27 0%, #1A1F3A 100%);
      color: white;
      padding: 70px 0;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: linear-gradient(135deg, #00F0FF, #0A0E27);
      border: none;
      color: white;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: filter 0.2s, box-shadow 0.2s;
    }
    .btn-primary:hover {
      filter: brightness(1.15);
      box-shadow: 0 0 18px rgba(0,240,255,0.45);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: var(--accent-cyan);
      font-weight: 600;
      padding: 12px 32px;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.08);
    }
    .hero-badges {
      display: flex;
      gap: 24px;
      margin-top: 32px;
    }
    .badge-stat {
      background: var(--accent-red);
      color: white;
      padding: 8px 18px;
      border-radius: 30px;
      font-weight: 600;
      font-size: 0.9rem;
    }
    .hero-image {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: 0 0 20px rgba(0,240,255,0.25);
    }
    .hero-image img {
      width: 100%;
      object-fit: cover;
    }

    /* sections */
    .section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .section-sub {
      color: var(--text-muted);
      margin-bottom: 48px;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      padding: 28px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      transition: 0.25s;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border: 1px solid rgba(0,240,255,0.3);
    }
    .icon-wrap {
      font-size: 2.4rem;
      color: var(--accent-cyan);
      margin-bottom: 20px;
    }
    .masonry-grid {
      columns: 3;
      gap: 24px;
    }
    .masonry-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      margin-bottom: 24px;
      transition: 0.25s;
      break-inside: avoid;
    }
    .masonry-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .masonry-card img {
      width: 100%;
      object-fit: cover;
    }
    .card-content {
      padding: 20px;
    }
    .tag {
      color: var(--accent-red);
      font-weight: 600;
      font-size: 0.8rem;
    }
    .compare-table {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .compare-col {
      background: white;
      border-radius: 16px;
      padding: 32px;
      box-shadow: var(--shadow-card);
    }
    .faq-item {
      background: white;
      border-radius: 12px;
      margin-bottom: 12px;
      box-shadow: 0 2px 10px rgba(0,0,0,0.03);
      overflow: hidden;
    }
    .faq-question {
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: #fff;
    }
    .faq-answer {
      padding: 0 20px 20px;
      color: var(--text-muted);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .cta-banner {
      background: linear-gradient(135deg, #0A0E27, #1A1F3A);
      color: white;
      padding: 64px;
      border-radius: 24px;
      text-align: center;
    }
    .btn-red {
      background: #FF2D55;
      border: none;
      color: white;
      font-weight: 600;
      padding: 14px 36px;
      border-radius: 8px;
      cursor: pointer;
      transition: background 0.2s;
    }
    .btn-red:hover {
      background: #D42A4A;
    }
    .footer {
      background: #0A0E27;
      color: #9CA3AF;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 32px;
    }
    .footer a:hover {
      color: var(--accent-cyan);
    }
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
      .masonry-grid { columns: 2; }
      .compare-table { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links, .btn-nav { display: none; }
      .hamburger { display: flex; }
      .hero-grid { flex-direction: column; }
      .hero-text h1 { font-size: 32px; }
      .grid-3 { grid-template-columns: 1fr; }
      .masonry-grid { columns: 1; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-badges { flex-wrap: wrap; }
    }