/* roulang page: index */
:root {
      --deep-rock-blue: #0B1A2E;
      --signal-cyan: #00E5A0;
      --cool-platinum: #C0CCD6;
      --surface-glass: rgba(18, 32, 48, 0.85);
      --bg-dark: #060F1A;
      --text-primary: #E5ECF3;
      --text-secondary: #9BA9B5;
      --border-dim: rgba(192, 204, 214, 0.15);
      --border-glow: rgba(0, 229, 160, 0.4);
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-mono: 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      background: radial-gradient(circle at 30% 10%, #1a2f45 0%, #0B1A2E 70%, #040b14 100%);
      font-family: var(--font-sans);
      color: var(--text-primary);
      line-height: 1.8;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    /* 自定义导航 - Mega Menu 基础 */
    .hth-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(11, 26, 46, 0.9);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(192, 204, 214, 0.1);
      transition: background 0.25s ease;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    .logo {
      font-family: var(--font-sans);
      font-weight: 700;
      font-size: 1.7rem;
      letter-spacing: -0.02em;
      color: #fff;
      text-decoration: none;
      display: flex;
      align-items: center;
    }
    .logo span {
      color: var(--signal-cyan);
      margin-right: 4px;
    }

    .nav-links {
      display: flex;
      gap: 2.2rem;
      align-items: center;
    }
    .nav-links a {
      color: var(--cool-platinum);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.25s ease;
      position: relative;
    }
    .nav-links a:hover {
      color: var(--signal-cyan);
    }

    .mega-trigger {
      position: relative;
    }
    .mega-panel {
      position: absolute;
      top: 45px;
      right: 0;
      background: rgba(8, 20, 33, 0.96);
      backdrop-filter: blur(20px);
      border: 1px solid var(--border-dim);
      border-radius: 16px;
      padding: 1.5rem;
      width: 520px;
      display: flex;
      gap: 2rem;
      opacity: 0;
      visibility: hidden;
      transform: translateY(10px);
      transition: all 0.25s ease;
      box-shadow: 0 20px 40px rgba(0,0,0,0.6);
    }
    .mega-trigger:hover .mega-panel,
    .mega-trigger:focus-within .mega-panel {
      opacity: 1;
      visibility: visible;
      transform: translateY(0);
    }
    .mega-col {
      flex: 1;
    }
    .mega-col h4 {
      color: var(--signal-cyan);
      font-size: 0.9rem;
      margin-bottom: 1rem;
      font-weight: 600;
    }
    .mega-card {
      display: flex;
      align-items: center;
      gap: 0.7rem;
      padding: 0.5rem 0;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .mega-card img {
      width: 44px;
      height: 44px;
      border-radius: 6px;
      object-fit: cover;
    }
    .mega-card span {
      font-weight: 500;
      color: #ddd;
    }
    .mega-card:hover span {
      color: var(--signal-cyan);
    }

    .mobile-menu-icon {
      display: none;
      font-size: 1.6rem;
      color: var(--cool-platinum);
      cursor: pointer;
    }

    /* 按钮与卡片系统 */
    .btn-primary {
      background: var(--signal-cyan);
      color: var(--deep-rock-blue);
      font-weight: 700;
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      border: none;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      text-decoration: none;
      box-shadow: 0 0 20px rgba(0, 229, 160, 0.5);
      transition: all 0.25s ease;
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      box-shadow: 0 0 32px rgba(0, 229, 160, 0.8);
      background: #00f0a8;
      color: #05101f;
    }

    .btn-ghost {
      background: transparent;
      border: 1px solid var(--cool-platinum);
      color: var(--cool-platinum);
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: all 0.25s ease;
    }
    .btn-ghost:hover {
      border-color: var(--signal-cyan);
      color: var(--signal-cyan);
    }

    .glass-card {
      background: rgba(18, 32, 48, 0.7);
      border: 1px solid var(--border-dim);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      backdrop-filter: blur(8px);
      transition: all 0.25s ease;
    }
    .glass-card:hover {
      border-color: var(--border-glow);
      background: rgba(18, 32, 48, 0.8);
      transform: translateY(-4px);
      box-shadow: 0 16px 40px rgba(0,0,0,0.6);
    }

    section {
      padding: 5rem 0;
    }

    /* Hero 双栏 */
    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.9fr;
      gap: 3rem;
      align-items: center;
      margin-top: 90px;
    }
    .hero-left h1 {
      font-size: 3.2rem;
      font-weight: 800;
      line-height: 1.25;
      letter-spacing: -0.02em;
      margin-bottom: 1.5rem;
    }
    .hero-left .sub {
      font-size: 1.2rem;
      color: var(--cool-platinum);
      margin-bottom: 2.5rem;
      max-width: 80%;
    }
    .hero-visual {
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: 0 0 40px rgba(0,229,160,0.15);
    }
    .hero-visual img {
      width: 100%;
      height: auto;
      display: block;
      filter: brightness(0.9);
    }
    .grid-overlay {
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: linear-gradient(135deg, rgba(0,229,160,0.1) 0%, transparent 80%);
      border: 1px solid rgba(255,255,255,0.1);
    }

    /* 亮点网格 4x2 */
    .highlight-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.8rem;
    }
    .highlight-card {
      padding: 1.8rem 1.2rem;
      text-align: left;
    }
    .highlight-card i {
      font-size: 2rem;
      color: var(--signal-cyan);
      margin-bottom: 1.2rem;
    }
    .highlight-card h3 {
      font-size: 1.3rem;
      font-weight: 700;
      margin-bottom: 0.7rem;
    }
    .highlight-card p {
      color: var(--text-secondary);
      font-size: 0.9rem;
      line-height: 1.6;
    }

    /* 案例瀑布流 */
    .case-waterfall {
      columns: 3;
      column-gap: 1.8rem;
    }
    .case-card {
      break-inside: avoid;
      margin-bottom: 1.8rem;
      background: rgba(18,32,48,0.65);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--border-dim);
    }
    .case-card img {
      width: 100%;
      display: block;
    }
    .case-content {
      padding: 1.2rem;
    }
    .case-tag {
      font-size: 0.7rem;
      background: rgba(0,229,160,0.15);
      color: var(--signal-cyan);
      padding: 0.2rem 0.8rem;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 0.5rem;
    }
    .case-metric {
      font-family: var(--font-mono);
      color: var(--signal-cyan);
      font-weight: 500;
    }

    /* 对比表 */
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      background: rgba(11,26,46,0.7);
      border-radius: 16px;
      overflow: hidden;
    }
    .compare-table th {
      background: #0B1A2E;
      color: #fff;
      font-weight: 600;
      padding: 1rem;
    }
    .compare-table td, .compare-table th {
      padding: 1rem;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .highlight-col {
      border-left: 2px solid var(--signal-cyan);
      background: rgba(0,229,160,0.03);
    }

    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .faq-question {
      background: transparent;
      color: #fff;
      padding: 1.2rem 0;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    .footer-brand {
      color: var(--cool-platinum);
    }

    @media (max-width: 1024px) {
      .highlight-grid { grid-template-columns: repeat(2, 1fr); }
      .case-waterfall { columns: 2; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-menu-icon { display: block; }
      .hero-grid { grid-template-columns: 1fr; }
      .hero-left h1 { font-size: 2.4rem; }
      .case-waterfall { columns: 1; }
    }