/* roulang page: index */
:root {
      --primary-deep: #0A0E27;
      --accent-cyan: #00E5FF;
      --secondary-violet: #6C3CE1;
      --text-body: #E0E6F0;
      --text-muted: #8892B0;
      --glass-bg: rgba(18,22,45,0.6);
      --glass-border: rgba(0,229,255,0.15);
      --card-shadow: 0 8px 32px rgba(0,0,0,0.4);
      --glow-cyan: 0 0 20px rgba(0,229,255,0.25);
      --radius-lg: 16px;
      --radius-sm: 12px;
      --radius-btn: 30px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", "Inter", sans-serif;
      --font-mono: "SF Mono", "Menlo", "Consolas", monospace;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--primary-deep);
      color: var(--text-body);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    a {
      color: var(--text-muted);
      text-decoration: none;
      transition: color 0.2s ease, text-shadow 0.2s ease;
    }
    a:hover {
      color: var(--accent-cyan);
      text-shadow: 0 0 8px rgba(0,229,255,0.4);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }
    /* 导航栏 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: rgba(10,14,39,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0,229,255,0.2);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--accent-cyan);
      letter-spacing: 0.5px;
      text-shadow: 0 0 12px rgba(0,229,255,0.5);
      white-space: nowrap;
    }
    .desktop-menu {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .desktop-menu a {
      font-weight: 500;
      font-size: 0.95rem;
      color: #B0B8D0;
      position: relative;
      padding: 0.25rem 0;
    }
    .desktop-menu a.active {
      color: var(--accent-cyan);
      border-bottom: 2px solid var(--accent-cyan);
      box-shadow: 0 4px 10px rgba(0,229,255,0.4);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 8px;
      z-index: 1100;
    }
    .hamburger span {
      width: 25px;
      height: 2px;
      background: var(--accent-cyan);
      border-radius: 2px;
      transition: all 0.3s ease;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      background: rgba(10,14,39,0.95);
      backdrop-filter: blur(20px);
      flex-direction: column;
      padding: 24px 20px;
      gap: 20px;
      border-bottom: 1px solid rgba(0,229,255,0.2);
      z-index: 999;
    }
    .mobile-menu a {
      font-size: 1.2rem;
      font-weight: 500;
      color: #B0B8D0;
      padding: 8px 0;
    }
    /* Hero */
    #hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 30%, #1A1F45, #0A0E27 80%);
      background-size: cover;
      padding-top: 80px;
      position: relative;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 3.2rem;
      font-weight: 700;
      letter-spacing: 0.02em;
      color: #FFFFFF;
      margin-bottom: 1.5rem;
      line-height: 1.3;
      text-shadow: 0 0 18px rgba(0,229,255,0.3);
    }
    .hero-sub {
      font-size: 1.25rem;
      color: var(--text-muted);
      margin-bottom: 2rem;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: #0A0E27;
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      border: none;
      box-shadow: 0 0 18px rgba(0,229,255,0.5);
      transition: all 0.25s ease;
      display: inline-block;
    }
    .btn-primary:hover {
      background: #33F0FF;
      box-shadow: 0 0 30px rgba(0,229,255,0.8);
      transform: scale(1.03);
      color: #0A0E27;
    }
    .btn-ghost {
      background: transparent;
      border: 1px solid var(--accent-cyan);
      color: var(--accent-cyan);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      transition: all 0.25s ease;
    }
    .btn-ghost:hover {
      background: rgba(0,229,255,0.1);
      color: #fff;
    }
    .hero-image {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-image .img-frame {
      background: rgba(18,22,45,0.5);
      backdrop-filter: blur(10px);
      border: 1px solid rgba(0,229,255,0.25);
      border-radius: 24px;
      padding: 12px;
      box-shadow: 0 0 35px rgba(0,229,255,0.2);
    }
    .hero-image img {
      border-radius: 16px;
      max-height: 400px;
      object-fit: cover;
    }
    /* 通用区块 */
    section {
      padding: 100px 0;
    }
    h2 {
      font-size: 2.2rem;
      font-weight: 600;
      margin-bottom: 0.75rem;
      color: #FFFFFF;
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 1.1rem;
      margin-bottom: 3rem;
    }
    /* 价值主张 非对称布局 */
    .value-layout {
      display: flex;
      gap: 24px;
      align-items: stretch;
    }
    .main-card {
      flex: 0 0 50%;
      background: var(--glass-bg);
      backdrop-filter: blur(16px);
      border: 1px solid var(--accent-cyan);
      border-radius: var(--radius-lg);
      padding: 2.5rem;
      box-shadow: 0 0 22px rgba(0,229,255,0.2);
    }
    .side-cards {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .side-card {
      background: rgba(18,22,45,0.5);
      backdrop-filter: blur(14px);
      border: 1px solid rgba(255,255,255,0.06);
      border-top: 3px solid var(--accent-cyan);
      border-radius: var(--radius-sm);
      padding: 1.5rem;
    }
    .card-icon {
      font-size: 2rem;
      margin-bottom: 1rem;
    }
    /* 功能标签切换 */
    .features-block {
      display: flex;
      gap: 2rem;
    }
    .tab-nav {
      display: flex;
      flex-direction: column;
      min-width: 180px;
      border-right: 1px solid rgba(255,255,255,0.1);
    }
    .tab-btn {
      background: transparent;
      border: none;
      color: var(--text-muted);
      padding: 1rem 1.2rem;
      text-align: left;
      font-weight: 500;
      border-left: 3px solid transparent;
      transition: 0.2s;
      cursor: pointer;
    }
    .tab-btn.active {
      color: var(--accent-cyan);
      border-left: 3px solid var(--accent-cyan);
      background: rgba(0,229,255,0.05);
    }
    .tab-content {
      flex: 1;
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .tab-panel {
      display: none;
      width: 100%;
    }
    .tab-panel.active {
      display: flex;
      gap: 2rem;
      animation: fade 0.3s ease;
    }
    @keyframes fade { from{opacity:0.5;} to{opacity:1;} }
    /* 时间轴 */
    .timeline {
      display: flex;
      justify-content: space-between;
      position: relative;
    }
    .timeline::before {
      content: '';
      position: absolute;
      top: 20px;
      left: 0;
      width: 100%;
      height: 1px;
      border-top: 1px dashed rgba(0,229,255,0.3);
    }
    .timeline-node {
      text-align: center;
      z-index: 2;
    }
    .node-circle {
      width: 16px;
      height: 16px;
      border: 2px solid var(--accent-cyan);
      background: #0A0E27;
      border-radius: 50%;
      margin: 12px auto;
    }
    .timeline-node:hover .node-circle {
      background: var(--accent-cyan);
      box-shadow: 0 0 18px var(--accent-cyan);
    }
    /* 案例大数字 */
    .stat-number {
      font-family: var(--font-mono);
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent-cyan);
    }
    /* 价格卡 */
    .pricing-card {
      background: rgba(18,22,45,0.45);
      backdrop-filter: blur(16px);
      border: 1px solid rgba(255,255,255,0.08);
      border-radius: var(--radius-lg);
      padding: 2rem;
      transition: all 0.25s;
    }
    .pricing-card.recommended {
      border: 1px solid var(--accent-cyan);
      box-shadow: 0 0 28px rgba(0,229,255,0.35);
      transform: translateY(-8px);
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .faq-question {
      background: transparent;
      width: 100%;
      text-align: left;
      padding: 1.2rem 0;
      font-weight: 600;
      color: #fff;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      border: none;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-muted);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-left: 1rem;
      border-left: 3px solid var(--accent-cyan);
    }
    /* 页脚 */
    footer {
      background: #060B1F;
      border-top: 1px solid rgba(0,229,255,0.1);
      padding: 3rem 0;
    }
    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; }
      .value-layout { flex-direction: column; }
      .features-block { flex-direction: column; }
      .tab-nav { flex-direction: row; overflow-x: auto; border-right: none; }
    }
    @media (max-width: 640px) {
      .desktop-menu { display: none; }
      .hamburger { display: flex; }
      h1 { font-size: 2rem !important; }
      h2 { font-size: 1.6rem; }
      .timeline { flex-direction: column; gap: 24px; }
      .timeline::before { display: none; }
      .tab-panel.active { flex-direction: column; }
    }