/* roulang page: index */
:root {
      --primary: #0AEFFF;
      --primary-dark: #00C8D4;
      --deep-blue: #0B1D3A;
      --accent: #FF6B35;
      --accent-hover: #e85a2c;
      --bg-light: #F8FAFC;
      --card-bg: #FFFFFF;
      --text-body: #1E293B;
      --text-muted: #5B6E8C;
      --border-light: rgba(0,0,0,0.04);
      --shadow-card: 0 8px 30px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 16px 42px rgba(0, 0, 0, 0.08);
      --radius-lg: 24px;
      --radius-md: 16px;
      --radius-sm: 12px;
      --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Inter', sans-serif;
      --max-width: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Inter', sans-serif;
      font-weight: 400;
      line-height: 1.65;
      color: var(--text-body);
      background-color: var(--bg-light);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    ul {
      list-style: none;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
    }
    /* 导航 */
    .nav-bar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(255,255,255,0.8);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(255,255,255,0.4);
      transition: background 0.25s, box-shadow 0.25s;
      padding: 16px 0;
    }
    .nav-bar.scrolled {
      background: rgba(255,255,255,0.98);
      box-shadow: 0 8px 28px rgba(0, 0, 0, 0.06);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
    }
    .logo a {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--deep-blue);
      letter-spacing: -0.5px;
      background: linear-gradient(135deg, var(--primary) 0%, var(--deep-blue) 85%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .desktop-nav {
      display: flex;
      gap: 2.5rem;
      align-items: center;
      font-weight: 500;
      color: var(--text-body);
    }
    .desktop-nav a {
      position: relative;
      padding: 8px 0;
      font-size: 1rem;
      transition: color 0.2s;
    }
    .desktop-nav a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s;
    }
    .desktop-nav a:hover::after,
    .desktop-nav a.active::after {
      width: 100%;
    }
    .desktop-nav a:hover {
      color: var(--primary-dark);
    }
    .mobile-menu-toggle {
      display: none;
      font-size: 1.8rem;
      color: var(--deep-blue);
      background: none;
      border: none;
      cursor: pointer;
      line-height: 1;
      padding: 4px;
    }
    /* 移动端导航菜单 */
    .mobile-drawer {
      display: none;
      position: fixed;
      top: 80px;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(20px);
      padding: 20px 32px;
      flex-direction: column;
      gap: 18px;
      box-shadow: 0 20px 30px rgba(0,0,0,0.08);
      border-radius: 0 0 28px 28px;
      z-index: 999;
    }
    .mobile-drawer a {
      font-weight: 600;
      font-size: 1.2rem;
      color: var(--deep-blue);
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
    }
    .mobile-drawer.show {
      display: flex;
    }
    .hero-cta-mobile {
      display: none;
    }
    /* 底部移动端胶囊导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 20px;
      left: 50%;
      transform: translateX(-50%);
      background: var(--deep-blue);
      backdrop-filter: blur(14px);
      padding: 8px 16px;
      border-radius: 40px;
      z-index: 998;
      gap: 16px;
      box-shadow: 0 12px 28px rgba(0,0,0,0.3);
    }
    .mobile-bottom-nav a {
      color: white;
      font-weight: 600;
      padding: 10px 18px;
      border-radius: 24px;
      font-size: 0.9rem;
      transition: 0.2s;
    }
    .mobile-bottom-nav a.cta-nav-btn {
      background: var(--accent);
      color: white;
    }
    /* 板块基础 */
    section {
      padding: 90px 0;
    }
    .section-header {
      margin-bottom: 56px;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--deep-blue);
      letter-spacing: -0.3px;
      margin-bottom: 16px;
      font-family: var(--font-heading);
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 1.1rem;
      max-width: 660px;
    }
    /* Hero */
    .hero {
      padding: 140px 0 80px;
      background: linear-gradient(180deg, rgba(10,239,255,0.04) 0%, var(--bg-light) 100%);
      margin-top: 0;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 3.4rem;
      font-weight: 800;
      line-height: 1.2;
      color: var(--deep-blue);
      background: linear-gradient(to right, var(--primary), #0088c4);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .hero-desc {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin: 24px 0 36px;
    }
    .btn-group {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
    }
    .btn {
      padding: 14px 34px;
      border-radius: 40px;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.25s;
      border: none;
      cursor: pointer;
      font-size: 1rem;
      background: none;
      text-decoration: none;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      box-shadow: 0 8px 20px rgba(255,107,53,0.28);
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 14px 28px rgba(255,107,53,0.35);
    }
    .btn-outline {
      border: 2px solid var(--deep-blue);
      color: var(--deep-blue);
      background: transparent;
    }
    .btn-outline:hover {
      background: rgba(11,29,58,0.04);
    }
    .hero-image img {
      border-radius: var(--radius-lg);
      box-shadow: 0 30px 50px rgba(10,239,255,0.18);
    }
    /* 亮点网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .feature-card {
      background: var(--card-bg);
      padding: 32px 28px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      font-size: 2.4rem;
      color: var(--primary);
      margin-bottom: 20px;
    }
    .feature-card h3 {
      font-size: 1.5rem;
      font-weight: 700;
      margin-bottom: 12px;
    }
    /* 产品瀑布流 */
    .product-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .product-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .product-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .product-img {
      height: 220px;
      background-size: cover;
      background-position: center;
      transition: transform 0.4s;
    }
    .product-card:hover .product-img {
      transform: scale(1.05);
    }
    .product-info {
      padding: 24px;
    }
    .product-info h3 {
      margin-bottom: 8px;
    }
    /* 对比表 */
    .compare-panel {
      background: white;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      display: grid;
      grid-template-columns: 1fr 1fr;
      overflow: hidden;
    }
    .compare-col {
      padding: 40px;
    }
    .compare-col.highlight {
      background: rgba(10,239,255,0.04);
      border-left: 3px solid var(--primary);
    }
    .compare-label {
      font-weight: 700;
      font-size: 1.1rem;
      color: var(--accent);
    }
    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 16px;
      max-width: 860px;
    }
    .faq-item {
      background: var(--card-bg);
      border-radius: var(--radius-sm);
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
      padding: 0 24px;
      border: 1px solid rgba(0,0,0,0.03);
    }
    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      text-align: left;
      font-weight: 700;
      font-size: 1.05rem;
      padding: 24px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--deep-blue);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-muted);
      border-top: 0px solid transparent;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 22px;
      border-top: 1px solid #eee;
    }
    .cta-banner {
      background: var(--deep-blue);
      border-radius: 32px;
      padding: 55px 40px;
      text-align: center;
      color: white;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      color: #B0C4DE;
    }
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .product-grid { grid-template-columns: repeat(2,1fr); }
      .features-grid { grid-template-columns: 1fr 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .compare-panel { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .desktop-nav { display: none; }
      .mobile-menu-toggle { display: block; }
      .mobile-bottom-nav { display: flex; }
      section { padding: 70px 0; }
      .section-title { font-size: 2rem; }
      .features-grid, .product-grid { grid-template-columns: 1fr; }
      .compare-panel { grid-template-columns: 1fr; }
    }