/* roulang page: index */
:root {
      --primary: #0AEFFF;
      --primary-dark: #00C8E0;
      --accent: #FF4D4F;
      --accent-dark: #E63946;
      --bg-white: #FFFFFF;
      --bg-light: #F7F8FA;
      --bg-dark: #0A0E27;
      --text-dark: #0A0E27;
      --text-body: #333333;
      --text-muted: #6B7280;
      --text-light: #E5E7EB;
      --border: #E5E7EB;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04), 0 4px 16px rgba(0,0,0,0.04);
      --shadow-glow: 0 8px 24px rgba(10,239,255,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --transition: 0.25s ease;
      --container-max: 1200px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Inter', sans-serif;
      background: var(--bg-white);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    button, input {
      font-family: inherit;
    }
    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--bg-dark);
      z-index: 1000;
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: baseline;
      gap: 6px;
      color: var(--primary);
      font-weight: 700;
      font-size: 1.5rem;
      letter-spacing: 1px;
    }
    .logo-icon {
      display: inline-block;
      width: 24px;
      height: 24px;
      background: var(--primary);
      clip-path: polygon(50% 0%, 0% 100%, 100% 100%);
      margin-right: 4px;
      transform: rotate(180deg);
    }
    .logo-domain {
      font-size: 0.7rem;
      color: var(--text-light);
      font-weight: 400;
      margin-left: 2px;
      opacity: 0.7;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      color: var(--text-light);
      font-weight: 500;
      padding: 8px 0;
      position: relative;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
      text-shadow: 0 0 8px rgba(10,239,255,0.6);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 3px;
      background: var(--primary);
      box-shadow: 0 0 12px var(--primary);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }
    /* Hero */
    .hero {
      padding: calc(var(--nav-height) + 60px) 0 80px;
      background: var(--bg-white);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-content {
      flex: 1;
    }
    .hero h1 {
      font-size: 48px;
      font-weight: 800;
      line-height: 1.2;
      color: var(--text-dark);
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-block;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      transition: var(--transition);
      text-align: center;
      cursor: pointer;
      border: none;
      font-size: 16px;
    }
    .btn-primary {
      background: var(--primary);
      color: var(--bg-dark);
      box-shadow: 0 0 12px rgba(10,239,255,0.4);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 0 20px rgba(10,239,255,0.7);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: var(--bg-dark);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      animation: pulse 2s infinite;
    }
    .btn-accent:hover {
      background: var(--accent-dark);
    }
    @keyframes pulse {
      0% { box-shadow: 0 0 0 0 rgba(255,77,79,0.5); }
      70% { box-shadow: 0 0 0 12px rgba(255,77,79,0); }
      100% { box-shadow: 0 0 0 0 rgba(255,77,79,0); }
    }
    .hero-image {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-image img {
      max-height: 420px;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.08);
    }
    /* sections */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      text-align: center;
      color: var(--text-dark);
      margin-bottom: 16px;
      position: relative;
    }
    .section-title::after {
      content: '';
      display: block;
      width: 80px;
      height: 3px;
      background: linear-gradient(90deg, var(--primary), var(--accent));
      margin: 16px auto 0;
    }
    .bg-light {
      background: var(--bg-light);
    }
    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: white;
      border: 1px solid var(--border);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-glow);
      transform: translateY(-4px);
    }
    .card-icon {
      width: 64px;
      height: 64px;
      margin-bottom: 20px;
      border-radius: 16px;
      object-fit: cover;
    }
    .card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
      color: var(--text-dark);
    }
    .card p {
      font-size: 15px;
      color: var(--text-muted);
      margin-bottom: 16px;
    }
    .card-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    /* 数据看板 */
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .data-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 28px 24px;
      border-left: 4px solid var(--primary);
      box-shadow: var(--shadow-sm);
    }
    .data-number {
      font-size: 40px;
      font-weight: 800;
      color: var(--accent);
      line-height: 1.2;
      margin-bottom: 8px;
    }
    .data-label {
      color: var(--text-muted);
      font-size: 14px;
    }
    /* 对比表 */
    .comparison-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      max-width: 900px;
      margin: 0 auto;
    }
    .compare-card {
      padding: 40px;
      border-radius: var(--radius-card);
      background: white;
    }
    .compare-left {
      background: #f2f2f5;
      border: 1px solid #ddd;
    }
    .compare-right {
      background: white;
      border: 2px solid var(--primary);
      box-shadow: 0 0 20px rgba(10,239,255,0.15);
    }
    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin: 20px 0;
      font-size: 16px;
    }
    .check {
      color: var(--primary);
      font-weight: bold;
    }
    .cross {
      color: #999;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-dark);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: #4B5563;
      padding-left: 16px;
      border-left: 3px solid transparent;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
      border-left-color: var(--primary);
    }
    /* CTA */
    .cta-section {
      background: var(--bg-dark);
      color: white;
    }
    .cta-form {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      justify-content: center;
      margin-top: 32px;
    }
    .cta-input {
      padding: 14px 18px;
      border-radius: var(--radius-input);
      border: 1px solid var(--border);
      background: white;
      flex: 1;
      min-width: 200px;
      transition: 0.2s;
    }
    .cta-input:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(10,239,255,0.2);
    }
    .form-note {
      text-align: center;
      font-size: 12px;
      color: #9CA3AF;
      margin-top: 16px;
    }
    /* 页脚 */
    .footer {
      background: var(--bg-dark);
      color: #9CA3AF;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer h4 {
      color: white;
      margin-bottom: 16px;
    }
    .footer a {
      color: #9CA3AF;
      display: block;
      margin: 8px 0;
    }
    .footer a:hover {
      color: var(--primary);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
    }
    /* 移动端 */
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .data-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: var(--bg-dark);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
      }
      .nav-links.open {
        display: flex;
      }
      .menu-toggle {
        display: block;
      }
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero h1 {
        font-size: 32px;
      }
      .section-title {
        font-size: 26px;
      }
      .grid-3, .data-grid, .comparison-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .cta-form {
        flex-direction: column;
      }
    }